block number help?

[JUSTa350]

I just pulled the motor out of my 86 k10, and i know it wasnt the original motor, but i cant find out what the motor was originally out of. the numbers behind the alternator are C8F398942 and D21OTWZ i could be wrong on some of the letters, im gonna go back out and check in a minute. but could someone tell me what its from please? ohh and the casting date was A118. if that helps? would that be january 11th, 78 or 88? its a 3970010 block, so im guessing 78?

 

[Swims350]

TWZ 78 350 Truck 165 LS-9 TH 350 4-Brl

 

[RetroC10Sport]

I just pulled the motor out of my 86 k10, and i know it wasnt the original motor, but i cant find out what the motor was originally out of. the numbers behind the alternator are C8F398942 and D21OTWZ i could be wrong on some of the letters, im gonna go back out and check in a minute. but could someone tell me what its from please? ohh and the casting date was A118. if that helps?

TWZ = 1978 LS9 truck 350 4bbl. A118 confirms it. A = jan; 11 = day; 8 = 1978

 

[JUSTa350]

sweet. you guys are awesome. thank you very much

 

[RetroC10Sport]

Beat me by one minute...

 

[Swims350]

lol