Hello, new to the forum. Need some help decoding a Chevy engine, a bit confused. It has the numbers 3970010 on the rear. Read somewhere that it means it is a 350 corvette block, not sure if true. On the front underneath the alternator area it has the numbers C5U152834, then V0730TYR. TYR indicates that it is from a bus or a van, but it can also mean it is a 305. I don't know how to decode the other set of numbers. Like to know exactly what it is, hope is not a 305. This engine already has a 268 cam and I want to install it in my 71 Chevelle.