[vern650]

the 496/8.1L is a very reliable motor and has been ran in high rpm marine aps. for many years and also in the 01-06(07 classic) GM 2500hd-3500 trucks flawlessly, atleast all the ones i know anyway. my brothers 03 chev 8.1 has over 200k on it and the only thing engine related he's ever had to replace was the water pump at like 180k. i dont know the difference between the factory 8.1l and say a 496 crate motor but if the crate motor is as good as the factory engine i wouldnt hesitate on a 496. you could probably pick up a wrecked truck with the 8.1l for about the same as a crate motor but then you'd have all the electrical for the efi, and also either an allison auto or a ZF6 6-speed to go with it. or find a used 8.1l engine for around a grand and give it a rebuild and some goodies and still probably be cheaper than a crate motor. the 8.1l that came in the gm trucks was rated at 340hp/455tq and with a raylar cam and heads and a good set of longtubes i've seen guys make well over 500hp. in my opinion the 8.1l was the best torque/towing gas engine ever put in a factory truck.