Originally Posted by johnswart
do you think this engine any good im putting it in a 1991 chevy pu 3/4 ton 4 wheel drive
Sure, as long as it's in good shape- no smoke or knocks, decent compression and vacuum readings and such.
It was made for a truck, but the factory timing curve and the camshaft leave a lot to be desired. They will hold the engine back from making the easy 450 HP that it is capable of. It will also need a set of headers and dual exhaust, preferably w/an "H" or "X" crossover after the collectors, but before the muffs.
Better heads would be desirable but not necessary for 450 HP. They can be ported to make (some say) up to 500 HP- but before I'd do it again (I ported a set of these heads before)- I would just go ahead and start w/a better factory head or an aftermarket head to begin with.