Hello and welcome the forum!
From the numbers you've posted, this is the most significant, V0421TKA, the Engine Assembly code.
It decodes as follows; V = Flint, MI (vehicle assembly plant), 0421 = April 21(date code), TKA = (Engine Assembly Suffix) = 1976, 350 CID, conv.cab, L, LS9 (options), 165 HP, 4 BBL, C-10 & 1500 (vehicle), or, 1978, 350 CID,conv. cab, m/t, L, LS9 (options), 165 HP, 4 BBL, C-10 & 1500 (vehicle)
The Engine Suffix Code is often reused, sometimes several times.
So, it looks like you've got either a 1976 or 1978 165 HP, 350 engine, that started out life in pickup.
Hope some of this helps!
Don't be a stranger on the forum, stop in from time to time and keep us informed on what your doing with your engine build.