Horsepower Ratings
 

Is there a way to tell how many horsepower my truck's engine was rated for? It came from the factory in 1971 with a 350 / 4bbl. Were there factory options for more HP or are they all pretty much the same? How do I hunt down the original factory HP rating? Thanks for any help.
-Chuck
:gmc2:

Re: Horsepower Ratings
 

That is an LS9 which was factory rated 255/355 hp/tq. (gross)

Re: Horsepower Ratings
 

The Truck Data Book for that year should have the info.

FWIW the 1969 350 4v was rated at 255 (Gross) @4600 RPM or 200 (Net) @ 4000 RPM. With the "A.I.R." Emissions pump it was rated at 195 Net

Re: Horsepower Ratings
 

71, I found 250 hp and 350 tq on this website. It's a PDF file.
http://www.gmheritagecenter.com/gm-h...olet-Truck.pdf
Scroll down to page 9. Your 350 is option LS9 on your SPID right?
Also your engine assy stamp might tell. It's stamped on the block on a pad just in front of the passenger side head. Get the suffix code at the end. (last 3 letters)

Re: Horsepower Ratings
 

GREAT website! Downloaded the PDF and will save that for future reference. Thanks!

Re: Horsepower Ratings
 

Apparently GM has recycled the LS9 nomenclature because this is what I get when I search the web for LS9 info:
The 2009 ZR1's LS9 engine develops 630 horsepower but actually has less displacement than the Z06's 505 hp LS7 engine (376 vs 427 cubic inches).
Wouldn't mind having one of them...

Re: Horsepower Ratings
 

"LS" engines nowadays are waaaayyyyyy different than the "LS" engines of yore... :)

Gary

Re: Horsepower Ratings
 

71, If you liked that you'll love this. This is the same website just a different page. From this page you can get to a pdf file for any year. Just scroll down to Chevrolet Trucks (all models not listed below) and click SHOW
http://www.gmheritagecenter.com/gm-h...tion-kits.html

Re: Horsepower Ratings
 

VERY COOL! Thanks.:gmc2: