ceub87

Hey guys, I'm new around here and have a '86 camaro that I'm thinking of swapping a GenIII for my sbc. I know a guy that has a complete engine w/ all acc and just missing the starter. He said its out of an '03 truck but he doesn't know what size the engine is. He pulled block #12551358, which is either a 4.8 or 5.3 (how can I tell the difference). Also the head numbers he gave me were 862. Could any of you help me find out what it is?

thanks
cj

Demon_Speeding

iTrader: (24)

Here's what I found. From automotiverebuilder.com;
"1999 - '04 Trucks
The 4.8L block was made of cast iron and carried a 12551358 casting number. This block was used from '99-'04 for all the 4.8L motors...The 5.3L engines had a longer stroke than the 4.8L, but they had the same bore so they shared a common block. All of the '99-'03 engines and most of the '04s came with the 12551358 cast iron block, but there were a few that had an aluminum block."

What sucks is that both the 4.8 and 5.3 used the same heads. From what I've read the only difference is the stroke of the crank and the pistons were dished on the 5.3 whereas the 4.8 uses a flat top.