I Found It!

[skipxt4]

Great stuff. That clears up, alot of questions, without answers, that I've had. Thank you Cecil.

 

[Iowa 409 Guy]

Thanks Cecil

Lot's of good reading there.

 

[NOS61RAG]

Nice!

 

[raymar58409]

Finally, after much research, I found the 61 production data revised Feb. 61 including the AMA Specs and a special supplement for the SS option and 409. Just about all the factory data you could want.

http://www.gmheritagecenter.com/gm-heritage-archive/docs/Chevrolet/1961-Chevrolet.pdf

Other years are available also at the GM Heritage Center website:

http://www.gmheritagecenter.com/gm-heritage-archive/vehicle-information-kits.html

Cecil, Thanks so much for posting this.So much for Barret/Jackson knowing what they are talking about. They stated that the '72 Monte Carlo was not available with an LS5. Well, I had one, and when I heard that I began trying to locate it to get it back. Based on what the original owner told me I thought maybe it was a one of deal. Now it doesn't bother me that I had to sell it. Although I wish I still had it. I don't understand the listing of only 270 HP for the LS5???

 

[Don Jacks]

Ray,in 1971 GM went to the "net hp rating'system.The ls5 in 1970,with a 10 to one compression on the "gross rating'system they used in those and eariler engines was around 345hp.This was on a blue printed engine with no accesories installed and headers.Your 72 had 8.5 compression,exhaust manifolds,most likely a retarded timing chain set-[same cam as the 325hp 396],and "smog"tuning .There is most likely the difference in the hp numbers.

 

[oldskydog]

Ray,in 1971 GM went to the "net hp rating'system.The ls5 in 1970,with a 10 to one compression on the "gross rating'system they used in those and eariler engines was around 345hp.This was on a blue printed engine with no accesories installed and headers.Your 72 had 8.5 compression,exhaust manifolds,most likely a retarded timing chain set-[same cam as the 325hp 396],and "smog"tuning .There is most likely the difference in the hp numbers.

Just like the dissapointment I felt in 71 when the new Corvette I ordered was only rated at 270hp (350, 4 spd).:

Ray, I have a buddy here that has an original Monte SS 454 for sale minus engine. I can't remember the year exactly, but I think it's a 70.

 

[raymar58409]

Just like the dissapointment I felt in 71 when the new Corvette I ordered was only rated at 270hp (350, 4 spd).:

Ray, I have a buddy here that has an original Monte SS 454 for sale minus engine. I can't remember the year exactly, but I think it's a 70.

Thanks Cecil, I'm not looking now, if I were that 61 impala of yours would have been gone.

 

[raymar58409]

Ray,in 1971 GM went to the "net hp rating'system.The ls5 in 1970,with a 10 to one compression on the "gross rating'system they used in those and eariler engines was around 345hp.This was on a blue printed engine with no accesories installed and headers.Your 72 had 8.5 compression,exhaust manifolds,most likely a retarded timing chain set-[same cam as the 325hp 396],and "smog"tuning .There is most likely the difference in the hp numbers.

Thanks Don, I thought of that later (net hp).

 

[58 Apache]

Hey Bob I agree with Mike

Bob can we make this a sticky? Its really great info that I think most of us go to on a regular basis.
Thank You

 

[oldskydog]

Finally, after much research, I found the 61 production data revised Feb. 61 including the AMA Specs and a special supplement for the SS option and 409. Just about all the factory data you could want.

http://www.gmheritagecenter.com/gm-heritage-archive/docs/Chevrolet/1961-Chevrolet.pdf

Other years are available also at the GM Heritage Center website:

http://www.gmheritagecenter.com/gm-heritage-archive/vehicle-information-kits.html

TTT for the Tech section.