Need help with finding the specs on a 1988 SBC 350

Cody3220

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OK so I have this engine that my girlfriends little brother gave to me. He pulled it out of a 1988 Chevy k2500 4x4. I wrote down all the numbers the engine has. And looked up the GM 5.7 LG SGI;
Head casting number is 14102193;
Side of the block is numbered 638;
The front of the motor by the passenger side valve cover reads V0510PJC. And if I'm reading the one below it right? it is CJE I90163.
Now the only thing that I could find is the 14102193.
Which the only thing it said was there junk heads!
I would like to find the specs about the motor rather then its just a TBI 350. Something like is it a 4 bolt main or 2 bolt? One piece seal? Roller cam or flat?
HP? Tq? What can I do with it? I would like to put vortec heads on it with a comp cam XM 270H flat tappit cam. Any help would be greatly appreciated! I'm trying to stuff it in a 1999 GMC Sonoma 4x4. thanks
 

63Half-ton461

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Cool! so first off 193 castings are NOT junk heads ! do not listen to the rhetoric of people who have never flowed a head let alone understand the principles behind how a flow bench even works. 193's are swirl port heads and in the hands of a decent porter can be made to flow very well with gobs of torque, i run em on my Malibu Skier and it pulls like mad out of the hole and has lots of top end speed. 193's work awesome with a carbed set up and decent intake and headers even in stock form with a 4 angle seat grind.

The 638 block is a one piece rear main, u will hav to drop pan to confirm 4 bolt main but if it came from a 2500 as opposed to a 1500 u are pretty much guaranteed it is a 4 bolt.
Being a 88 (a transition year)there is a good chance your fuel pump drive shaft hole has been bored and the motor has a block off plate. So u can mount a mechanical fuel pump.
An easy way to tell if it is a roller or flat tappet is pull a valve cover and look down past the push rod to see the top of the lifter, if there is a dog bone there its a roller if not its a flat tappet.
That marine cam you picked is a little big for a 4x4 with only 350 cubes and that 112 degree lobe separation is giving up bottom end for top end you'll rarely use. it will probably have a nice sounding idle thow.
I would look at the 268 high energy with 110 LSA as a better 4x4 cam , probably one of comps best selling flat tappets
 

Cody3220

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So you think I would like the 268 better? Right on. Well its a two bolt main. I pulled the hole thing apart and cleaned the heck out of everything on it. I would like to stick vortec heads on it. But I'm looking for a torque monster rather then high HP. I still want to drive it around and pull with it sometimes what do you think?
 

63Half-ton461

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My buddys 80 blazer with a 350 had the 268 cam in it , he had a lobe go flat so he pulled the motor, i installed a comp high energy 260H, Erson single idler gear drive and 1.6:1 rockers, his heads were the early style double bumps , so the heads were nothing special but better than open chamber smoggers, we were amazed at how nice that motor pulled afterward.

Buddy of course with all that torque he blew the thing up after that, busted the piston tops.

If you go to the Comp web site they have dyno charts for their Extreme Energy line, You can see that with a 350 after about 212 degrees of net duration you start shifting torque away from the bottom end up the power curve, when you get into the bigger cams you're actually giving up quite a bit and this is where people start running lower rear gears and looser torque convertors to compensate.

If your motor is not to worn out i would just do a refresh with everything that's there, 2 bolts are fine if they are in the sub 500 hp range. (maybe its the 1 tons where 4 bolts are more of a guarantee)
When you get the heads redone make sure u get the 4 angle seat grind, the 193 is the forerunner to the Vortec and they have similar combustion chambers , the Vortec is actually a swirl port head as well but with a different approach using a angled port floor and bowl biasing, people rave about the Vortec but if you want torque and fuel efficiency the 193 is tough to beat. Don't let anyone tell u 193's can't pull to 5k rpm , 193's have bigger ports than people realize and were designed by some smart people. If you go with vortecs don't use the Performance Products intake as the last one i will ever buy from them had horindus fit up and super rough internal casting.....
 

Cody3220

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Yeah I hear that! When I went and took the engine apart my brother trashed the cam pulling it and mangled the bearing. His first time taking a motor apart lol. So I'm going to go with new fresh equipment. What do you think of the scat cranks? I want my Sonoma to have guts. But nothing radical. I don't know any shops so in basically I'm doing everything my self
 

63Half-ton461

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I have bought both Eagle and Scat and i liked the scat better as it had a bit more meat to it but both cranks have mic-ed spot on so if i scored another Eagle like i did a few years back for 99 bucks on ebay its hard to go wrong, having a worn crank machined isn't getting any cheaper but a new crank wont be balanced so either way its gonna cost something. Don't be afraid to make a ebay seller an offer ive made a few deals that way.
I have a 88 s10 2wd rc sb with a v8 so i'm familiar with the swap , seems to me i recall the 4x4 needing a custom oil pan
 

Cody3220

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yeah its a hamburgers oil pan PN -1109. the old crank I pulled out is pretty hammered. I was deciding to go with a eagle or scat. I have done some reading on both of them and it seems you can't really go wrong with either one. Do you know how much ball park figure would be for balancing?
 

63Half-ton461

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On the cranks i look at that last web cause if a crank is gonna break , that is where it will be , think about it , all the power generated by the motor has to go through that last web. So for me comparing 3.75" internally balanced cranks from Scat and Eagle i thought the Scat had a little more meat there, as for their 350 cranks i dont know + not as critical on the shorter stroke cranks anyway.

Balancing is 99% labour so if you balance your own rods and your pistons are already weight matched and you hand the machinist a rod, piston/pin, 2 rod bearing shells and a set of rings for one piston he can figure out bob weight and should be able to balance your crank in under 2 hours.
If he has to balance your rods and mount your pistons add 1-2 hours so whatever the shop rate is x time , ball park $200-500

On the late model Small blocks with the one piece rear main seal If you choose to go with a internal balance crank (which will have more material in the counterweights) you will have to source a neutral balance aftermarket flexplate so you may as well factor that into the cost of the crank.
 

hurst01

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I have been off the forum for a pretty good while because of health reasons. Have you done anything with the engine yet? Half-ton has given you some decent advice but I didn't see whether you were going to stroke the engine or stay with the 5.7. You can build a 377 or 383 stroker for close to what you can do with the 5.7.
As far as balancing, you can purchase a 383 Stroker kit (balanced) for just a few dollars difference in the un-balanced kit. A 383 Stroker (typically) consists of a 350 block bored .030 with a longer 3.75" stroke. The stock 350 has a 3.48" stroke. Two bolt Chevy blocks very much proved themselves long before the 4 bolt engine ever came along so that is not a concern.
If you haven't already, when you have the cam bearings replaced, go with the fresh .030 bore UNLESS the stock bore is good. NOTE: A 350 with stock 4.000 bore and a 3.75 stroke crank makes a 377 cu in. A .030 over block and a 3.75 crank is 383. I have built and used both. Standing side-beside, no one can tell the difference and you more than likely won't even notice a difference driving. By using a stock bore you can save the cost of boring the block, but either way the pistons will have to be replaced because of the relocation of the wrist pin holes.
You will get the most bang for your buck by going with a stroker. You can find a stroker kit in many configurations. If you get a balanced kit with flywheel it might save you a bit of hassle but I have found that a lot of balanced kits with flywheels come with a 168 tooth flywheel, whereas most late model flywheels are 153 tooth. I much prefer the 153 tooth because I don't have to change out the starter for one that will work with the 168T. The stock flywheel (assuming it is for automatic) has a counterweight that you can remove making it a neutral flywheel and it works fine, might even save you a few $$$.
The block will probably have to be ground for clearance of the longer stroke crank. I have found some mid-90s blocks that I was able to stuff the 3.75 crank in without grinding. If needed, I can send pics of where the block has to be ground for clearance. This needs to be done BEFORE sending to the machine shop for cleaning because the dust from grinding makes a mess and you certainly don't need it in your new engine.
I can normally build a stroker engine for about $1500 for everything unless I start changing the intake or other things. I actually found a guy that regrinds cams to your desired specs that I have used very successfully. I save about a hundred dollars on each cam. Not necessarily recommending this but if money is tight??
 

63Half-ton461

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Ed , (Hurst01) feel free to jump in and share your knowledge on any threads that i'm on, always nice ta hear other folks perspective on all things mechanical, nice to meet cya , Pete
 

Cody3220

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So you said that some of the 90's would just fit a 3.75 crank? What would it take for a 1988 block to fit. Can you send me where I would need to notch out the block?
 

63Half-ton461

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Notching out your block is not your main concern, far from it in fact.
Your main concern is getting your connecting (4 specifically) rods to not hit or near miss the camshaft.
This is why when GM produced the 400 (which has a 3.75" crank) they used different (dropped shoulder/shorter) con rods than what is/are in the 350.

When building a 383 using 350 rods (which is what 90%+ builds use) you have to "mock build" the engine first (even if u buy a complete rotating assembly) to check for interference.
Basically u assemble the short block with crank and camshaft (timed in) and NO piston rings , this way u can rotate the thing and easily re & re (hand torqued bolts) piston and rod assembles as u go and do checks.

So you start at the front, work your way back installing piston and rod assemblies and rotating the crank to see where the con rod big ends hit or near miss (cam & block), u use feeler gauges to check clearances and adjust (by grinding) accordingly.

I use 0.066" as a safe clearance dimension , others may go tighter or looser.

Now i use ether Chevy PM rods or aftermarket Scat, Scat copy (cap screw) rods , 4 of your rods are gonna need clearancing if using chevy PM rods , 1 or 2 actually hit the cam so will need more grinding to clear and this is where extreme care and multiple measurements is required, and small careful material removal is done.

U can have your feelers taped to a rod (to get em up in there) and you can paint the feelers to leave witness marks and show you precisely where u need to grind.

What u have to do to the Scat rods depends which rods you get, some have profiled shoulders some don't, their budget HD I beam rods look like they are a through bolt to cap screw conversion. Speedmaster sells a Scat copy on ebay that im fitting into a 334 that i'm currently working on, we'll see how that go's....

Building a 383 may not cost to much more but they have a steep learning curve when it comes to picking parts and fitment prior to assemble.

That being said, the 383 truly is a kick ass motor !!! once you've had one to play with, the 350 will always look like a compromise on subsequent builds.....
 

Cody3220

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Well since it sounds like you have been doing this for a while, I guess I'll just load you up on a flight to Idaho . Then after we get the hog built go for a roll up in the hills. No but seriously. I'm thinking the 377 should work more for what I would like. What's your thoughts on a NV3550 five speed behind it? I want to have total control of the motor. Thanks for getting back to me. Your a big help.
 

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63Half-ton461

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i built a 377 yrs ago it was my first real stock car motor i later went to a 400 which was a explosive beast.

Ive never run a 3550, in have one sitting in my shipping container so maybe someday, im a wide ratio 4 speed fan in my hot rods, the truck in my avatar is a big block (454) 4 speed , the shifter is 2 and a half feet tall so people can see me shifting gears through my back window as im leaving then from the light. LOL
 

63Half-ton461

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I built the 377 with a 400 block and a 350 crank, do you know that you need a bearing spacer kit to make the 350 crank fit the 400 mains ? you can use 400 pistons but ya gotta have the 350 rods to make that work ......

So 400 block, spacer kit, 400 pistons, 350 crank and rods ....... have the whole mess balanced run some nice 2.02 heads and you have one sweet little motor that will buzz well into the 6's
 

Cody3220

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Yeah that sounds like a hell of a beast. But for being in a 4x4 going that quick. I don't really want to get it stuck in the top of a tree lol. Damn! 6is???? But he'll, that does sound like a blast! " Boy's you see that fishing spot across the river? We don't need no boat!
 

hurst01

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I don't use a 400 block for my 377. You can take a stock bore 350 and add the 3.75 stroker crank and you got it. A 383 is typically a 350 block bored .030 over with a 3.75" stroke. Use a stock 4.000 bore and it is a 377. For me, using the 400 block is too much of an expense, with the bearing spacer kit and a lot of extras to make it all work together.
You can get a stroker kit on ebay (priced anywhere from $750 -$2000) that has the 4340 rods that are already clearanced for the cam, most of them are. If you are going to order a cam you can also order it as a small base circle and that cures another problem. A 377 is great if you have a stock 350 with a really good bore, otherwise you bore it .030 over and make it a 383. Honestly, standing side-beside I challenge anyone to be able to tell the difference between a 383 and a 377 unless they tear it down or do a cylinder volume test, and what is the likelihood of that? And who cares anyway? You can also get the stroker kit that will use either a stock length 5.7" rod or a 6' rod. Just FYI, the longer rod is preferred but it gets very close to the ring lands in the piston. So, I go with the 5.7 rod. There are many stroker kits available. Scat, Eagle and several others. If you purchase unbalanced it will cost you another couple hundred bucks for balancing. I normally buy balanced. Another FYI (see below), I mention that I am building 3 1995 LT1 engines. The LT1 engine is an INTERNAL BALANCED engine with a neutral balancer AND flywheel. Careful to not mix them up. Almost forgot, I always but with free floating (bushed) rods that I can assemble myself and not have to pay to have pressed fit. You have to pay extra for the bushed rods but cheaper than a press fit installation. I am all about saving money, besides the free-floating rods are high performance.
The new rods that come with the stroker kits should have cap bolts instead of studs and nuts. That helps a lot of clearance issues. You can also order the striker kits already balanced and that does away with another issue. The can be purchased with or without a flexplate (flywheel). I don't really like that because a lot of the kits come with a 168 tooth flywheel and most modern day engines use a 153 tooth flywheel, which I prefer. if you should get one without the flywheel the 153 tooth flywheel typically has a counterweight welded to it. If you purchase a balanced assembly all you have to do is drill the welds on the counterweight and knock it off making the flywheel a neutral balanced flywheel.
I am not big on having the use the 400 harmonic balancer. That is another thing, you can get a stroker kit that requires a external balanced flywheel and a neutral harmonic balancer, thus not needing the 400 balancer.
Yes... I found a 1996 Chevy 350 engine in a Pull-A-Part junk yard, purchased the complete engine and when I had time stuffed the 3.75" stroker crank in it with absolutely NO block grinding. BTW, recommended minimum clearance is about .020" I could not believe it. Half-ton is right on assembling one rod and piston with no rings for a test fit. It is all bolted to the crank and CAREFULLY turned to check for clearance and marking in each cylinder. And he is also right. All of this has to be done before sending out for cleaning because all the grinding dust makes a real mess and it has to be flushed.
Just remember, if using a 400 block with a 350 stroke crank, OR a 350 block with a 3.75" stroke, the longer stroke crank will make more torque and with a smaller bore will be a bit cheaper to run. Same cubic inch.
I am currently building a 377 and a 383, along with a 355. All three are 1995 LT1 engines. I have another 1996 355 (350+.030) block that I am unsure of what to do with right now. It was a fresh bore but has some strange looking stains in one of the cylinder walls as though it might have needed another .010.
As of right now, I can't remember if I have ground my 377 block for clearance or not... been too long. If not, I can mark it where it needs grinding and if I have, I can take some pictures of it. I already had the 377 pistons on rods from another build and the owner decided he wanted 383 instead, so I pulled it down and bored the block, bought new .030 pistons for a 383 and he has a 383 now. It certainly was not worth the extra expense of tearing it down just for .030 but that is what he wanted. He really would not have known the difference but he kept telling people it was a 383 and finally I corrected him and he had me tear it down to make a 383 out of it. The 377 had only run for about 30 seconds. I guess, what ever floats your boat! OK, you have two different perspectives on how to build either a 377 or a 383. All you have to do now is choose. Given time to shop a bit, I have actually built a 383 stroker for about $1200 plus machine work.
 

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