Pat McPherson

The easiest way I know to tell is if there are provisions for a mechanical fuel pump. Gen IV blocks can run a Mechanical fuel pump. On Gen V blocks the boss is not there or at least not machined.
Another way is the rear main seal. Gen IV has a 2 piece, Gen V a single piece.
A 1990 and 1992 block should be the same. Gen V production block are from 1990 to 1995.

DURANGOKID59

Thanks Pat, thats a big help. Ive asked a few marina's and engine shops around here, and I cant really get a straight answer. Some say yes, no problem, others say completly different, wont work. So, I need to make sure the block is the same gen, and change pistons and cam. Other than that I should be good to go?

Wobble

Get the casting numbers off both blocks and go here http://www.mortec.com/bbc.htm just about the last word on gm casting numbers, they have crank, head and intake numbers also

Pat McPherson

The truck engine may or may not have a forged crank and 7/16 bolt rods like your 454Mag, but at HP levels below 450, it does not matter much.
I'd say yes, if the blocks are the same Gen, new pistons, rings, bearings, cam, timing chain, oil pump, gaskets,..., and you should be good to go.
Good Luck with your project...

DURANGOKID59

Thanks Wobble, I think that will be a big help once I get some numbers together and see what Im actually working with.

DURANGOKID59

Thanks Pat, either way I look at it Im still going to be spending a chunk of change, so Im trying to figure the most economical way to do it. I guess Ill have to add it all up and see where the $ falls. Thanks for the help guys.