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oldskool · 09-26-2021, 10:57 AM

"...No 71 Firebird seems to fit I/SA=11.00
Ideas?

Well, IF they had the '71 year correct, then the 300hp 400 would work with some of the heavier bodies.

Do you know what the exact NHRA hp factor was, for this engine at the time of that race ???

http://www.classracerinfo.com/Engine...px?ENGINE=2058

At 300hp, anything between 3600lbs & 3750lbs would fall into I/SA. 12 x 300 = 3600 12.5 x 300 = 3750 There are several '71 Pontiac bodies that could work, including the most likely GTO, depending on what the exact NHRA hp factor was for that particular body at the time of that race.

Hey, they could have swapped out the '70 front cap on the '70 Viking GTO, for a '71 GTO front cap & changed to the '71 300hp engine. Lots of Pontiac guys have done this kind of swapping around, especially on the '70-'73 Birds. I assume that any '70 or '72 GTO could be changed into a '71, with the correct parts swap.

I just noticed that you said: I/SA = 11.00. So, was that the case in 1971 ? I ask, since now: I/SA = 12.00. ???

http://www.classracerinfo.com/NHRA_Classes.aspx

Just looked in the Jr. Stock book. In '71, I/SA was indeed 11lbs/hp. Then, for '72, things REALLY got shook up.

The '72 Tons-a-Fun wagon was running I/SA in the pic below. So, I suppose some '71 wagons may could have run I/SA, at some point, in the earlier days.

Another possibility is that Arnie was driving someone else's car at that race. It has happened LOTS of times. So, we don't really know what car he was driving at that race. We just ASSUME that they had the '71 Pontiac correct. They recently had Bruce Noland listed as driving a Corvette, when he was actually driving his new '69 T/A clone.

09-26-2021, 10:57 AM	#5
oldskool VIP Member Join Date: Dec 2014 Location: The Land of Bayous, Boudin & Crawfish Posts: 1,668 Likes: 223 Liked 750 Times in 361 Posts	Re: 1971 US Nationals class winners. "...No 71 Firebird seems to fit I/SA=11.00 Ideas? Well, IF they had the '71 year correct, then the 300hp 400 would work with some of the heavier bodies. Do you know what the exact NHRA hp factor was, for this engine at the time of that race ??? http://www.classracerinfo.com/Engine...px?ENGINE=2058 At 300hp, anything between 3600lbs & 3750lbs would fall into I/SA. 12 x 300 = 3600 12.5 x 300 = 3750 There are several '71 Pontiac bodies that could work, including the most likely GTO, depending on what the exact NHRA hp factor was for that particular body at the time of that race. Hey, they could have swapped out the '70 front cap on the '70 Viking GTO, for a '71 GTO front cap & changed to the '71 300hp engine. Lots of Pontiac guys have done this kind of swapping around, especially on the '70-'73 Birds. I assume that any '70 or '72 GTO could be changed into a '71, with the correct parts swap. I just noticed that you said: I/SA = 11.00. So, was that the case in 1971 ? I ask, since now: I/SA = 12.00. ??? http://www.classracerinfo.com/NHRA_Classes.aspx Just looked in the Jr. Stock book. In '71, I/SA was indeed 11lbs/hp. Then, for '72, things REALLY got shook up. The '72 Tons-a-Fun wagon was running I/SA in the pic below. So, I suppose some '71 wagons may could have run I/SA, at some point, in the earlier days. Another possibility is that Arnie was driving someone else's car at that race. It has happened LOTS of times. So, we don't really know what car he was driving at that race. We just ASSUME that they had the '71 Pontiac correct. They recently had Bruce Noland listed as driving a Corvette, when he was actually driving his new '69 T/A clone. Attached Thumbnails Last edited by oldskool; 09-26-2021 at 12:58 PM.