Hope someone can help me. I have a '72 corvette and have found the following engine ID numbers. I know this is not the original engine - can you help me determine what it is and where it came from?

V1001TWZ
T8S504587

Thanks for your help.

Its a 1978 truck engine.

V1001TWZ is the engine application code
V=Flint Engine Plant
10=Oct
01=Day of month
TWZ=1978 Chev or GMC truck 350-4BC, RPO LS9, 1/2 and 3/4 ton conventional cab, 2x4 and 4x4.

T8S504587 is the VIN code
T=GMC Truck
8=1978
S=Assembly Plant, St Louis or Mexico
504587=Vehicle serial number