I bought a donor truck this weekend for the motor and transmission. The seller said the truck was a 305 originally but that the motor has been replaced with a 350 by a previous owner. I tried to locate the casting number to determine what I have and I found this cast in the block back behind the driver side head:

-a sidways 8, followed by the GM script and
"5.7LG SGI"

I asssume the "5.7" means 350 but where from this casting is the actual casting number? Thanks, Scott


1947, 1950, & 1952 Chevrolet 1/2 ton
1952 GMC 450 series Cab Over Engine
1946 Chevrolet 2 Ton