Would anybody happen to know the factory rating for a 71 buick lesabre custom, with dual exhaust, 4 bbl, no ac and an automatic (th350). I've been combing the net for the last 4 hours and found nothing. Any help is appreciated.

a th350 indicates a 350ci engine as all of the 455s came with a th400 that year.

this means a TD code engine with 260hp@4600rpm and 350tq@3000rpm.

info found in Petersen's Big Book of Auto Repair: 1977 edition.

1971 was the last year of gross hp ratings so the factory was rating this motor without accesories. IOW, you won't find a seperate listing for air/non-air. expect ~10-15% less at the rear wheels.

Thanks for the help. I did come across the 260 hp rating last night while searching, but it was for a 71 buick GS. So I had figured that they must come with at least a different cam to make that kind of hp. Well learn something new everday, thanks again.