Yes, you could get the 3-71 factory in 52 and 53,in the 450 and 470 series GMC trucks. It is a high block, rated 105 hp factory. I want to use the 4 valve head for sure so I can use Jake brakes. Might go ahead and turbo it also. I think 160-175 horse is attainable with a little boost.
There was a guy that replied to an old post about 3-71s, his handle is WV Ike. Said he has dyno'd some and I would like to hear the results. WV Ike, do you still hang out here?