I pulled this motor out of a 96 pu. The owner said it was'nt the factory engine, but he wasnt sure what it was. It ran fine, no knocks but smoked like a train. The casting numbers are 10243880 thanks

Front of the block , pass side is a pad with letters stamped in it.That will tell you exactly what size / Hp / trans the engine was originally. Block casting means little as one casting may have been used for several different engines

10243880 lists as a 96-00 block 1 pce seal roller cam block. Could be Vortec truck ( 2 or 4 bolt mains), could be ZZ4 or a GMPP crate engine. Same block used
Pull rocker covers and see what the heads casting # are
How many bolts holding the intake down?

head casting numbers are 14102193

Ok I'm kinda dumb when it comes to identifying engines by numbers and letters how would i go about decodeing in lol

If stock block and not machined should have 3 letter code as well as some numbers stamped on the pad.
Google the 3 letters or post up here

http://www.thirdgen.org/techboard/te...tyle-head.html (14102193 a vortec style head?)

http://www.thirdgen.org/techboard/te...der-heads.html (14102191 and 14102193 cylinder heads)

http://www.thirdgen.org/techboard/te...4102193-a.html (which heads are better??? 14102187 or 14102193)