Lookin for NHRA Stock Class ET/MPH from 1970-71

[Dwight Southerland]

I have Classification Guides for that era. Since that was before the days of factoring and weight adjustment, the body-engine combinations could be narrowed down, if you would be interested. The 1957 Chevrolet Q/S would be a 265-162hp, not a 283. Technically, the 283-185hp engine was for automatic transmission only, though that was blurred from the beginning.

[DeuceCoupe]

Originally Posted by Dwight Southerland

I have Classification Guides for that era. Since that was before the days of factoring and weight adjustment, the body-engine combinations could be narrowed down, if you would be interested. The 1957 Chevrolet Q/S would be a 265-162hp, not a 283. Technically, the 283-185hp engine was for automatic transmission only, though that was blurred from the beginning.

Very much interested. I have the Rule Books from 1958-1968 (but not 1969-71) but the only Classification Guides I have are the current ones on line. There are good to get weights, but still a big spread eg 57 Chev from lightest to heaviest. So just knowing its a 57 Chev doesn't mean much. And of course 68 Chev could mean big car, Chevelle, Camaro.


For example, in the sheet Rich B already posted it lists Kost's W30 in F/SA. NHRA says 3720lb for the 442 W30 and 3720/370 puts it in G/SA in 1970. So I figure, well maybe it was a plain Cutlass at 3607lb which works for F/SA. If I didn't guess at some stuff I wouldn't get very far.


I think they were factoring some stuff by 1968-1970 eg Ford's 428cj got factored right away to 360hp - different for ramair and non-ramair too. But they hadn't gone factor-crazy yet.


I could sure use that Classification Guide info but not sure how to get it from you, that's a lot of info unless its in a PDF you could Email.

[Dwight Southerland]

Sorry, but the Class Guides I have are red binders, no PDFs!

[DeuceCoupe]

Originally Posted by Dwight Southerland

Sorry, but the Class Guides I have are red binders, no PDFs!

I am really just looking for HP-FACTORS, ie engines where NHRA changed the ratings. For example the 428cj was 335hp from Ford.
NHRA factored it to 360hp.
Then I THINK they factored the flat-hood-non-ram-air version to 340hp, I know it was different than the ram-air.


I think stuff like the 302z28, Mopar 340, Ford 427, Chev 396/375 and 427s, Chev 350/255 LM1, maybe the LS6 and 455/w30 also got factored pretty quick.


That's really the info I need, hard to imagine they could change all the shipping weights so I assume the online stuff today is as good as any on those.


Thanks if you can list any of those factors!

[Rich Biebel]

There was no factoring back then. Factory HP ratings stood and shipping weights as listed in the guide book. No driver weight was added. A car was weighed by itself and had to have 5 gals of gas in it. That was very specific and it cost us a record once. Pretty silly since the driver weighed 200 lbs.
The man who had the ultimate say on all of it was Farmer Dismuke. What he said was final. He could change a HP rating I believe. You have to keep in mind stock back then was not "Stock". Aftermarket pistons and rings other than stock were allowed. Cams were definitely not stock. New cars cost a lot of $$$ and the old cars were much more readily available, cheaper and proven combos. New cars were run by people with dealership connections or maybe factory support. And any new car/engine combo was a bit of a risk to see how fast it could run. For instance......the 1969 350/255 Chevy was not real popular at first until others showed how good it could run. The lower compression ratio made people hesitant to run one.The class guide book was huge....and cost some $$. People used to sit and dig thru it looking for good looking combinations. They still do! 2 books. Class guide and engine blueprint specs. All available now right here thanks to Dwight.

[Ed Wright]

Originally Posted by Dwight Southerland

I have Classification Guides for that era. Since that was before the days of factoring and weight adjustment, the body-engine combinations could be narrowed down, if you would be interested. The 1957 Chevrolet Q/S would be a 265-162hp, not a 283. Technically, the 283-185hp engine was for automatic transmission only, though that was blurred from the beginning.

I had one of those, finally fell apart.