69 Chevelle AA/SA 10.04 at 125mphat Spring Nats
 

Austin Williams in seat,Is this a 427-425HP combo to run AA/SA??

Re: 69 Chevelle AA/SA 10.04 at 125mphat Spring Nats
 

Yes.

Re: 69 Chevelle AA/SA 10.04 at 125mphat Spring Nats
 

How did an 69 Chevelle 427/425 automatic make AA? The 69 Chevelle 427/425 automatic is a natural B car. We even asked if using aluminum heads to make the HP factor 435 would make it a natural A car with an automatic, and were told "no". The automatic has been a natural B car for as long as I can remember, back to when Harry Vineyard ran one back in the eighties and early nineties.Harry drove the car with an automatic in B/SA, and it was a killer. They put the 4 speed in and Tucker Parrish drove it in A/S, and it was just as wicked. I think Kevin Borgstrom put the 4 speed in his beautiful green Yenko clone just to run AA.

Re: 69 Chevelle AA/SA 10.04 at 125mphat Spring Nats
 

Alan, Don`t stick & automatic fit the same class`s? stick 8.36, automatic 8.49.

Re: 69 Chevelle AA/SA 10.04 at 125mphat Spring Nats
 

A= 8.00 lbs - 8.49 lbs per NHRA. A car can move up or down one class from natural class. So the car is a natural A car at 8.49 with the automatic. To fit AA/SA the car with driver would weigh 3355# min. to 3565# max.

Re: 69 Chevelle AA/SA 10.04 at 125mphat Spring Nats
 

looks correct to me, by NHRA,s guide it's a natural A car , I did notice that Dwight's site lists the auto as falling at 8.50, and nhra says 8.49. not sure why they are different.

These cars have been run as A cars for ages, Denny Ford and Jim Benjamin both ran them as sticks back in the 70's and 80's , long before we could move a class up or down and I don't think the rating has changed

Re: 69 Chevelle AA/SA 10.04 at 125mphat Spring Nats
 

NHRA had originally rounded the 8.49*** to 8.50 which wasn't right.

Re: 69 Chevelle AA/SA 10.04 at 125mphat Spring Nats
 

The 8.49 has always been rounded to 8.50, and as recently as a year or so, when I looked, NHRA policy was anything over 0.25 pounds was rounded to 0.50 pounds for classification, as written in the rule book. I was looking at buying an already finished car a couple of years back, and NHRA told us in no uncertain terms that the 427/425 in the 69 Chevelle was 8.50 natural with the automatic, and we could not put the car in AA with an automatic.

By absolutely no means am I complaining, I actually hope that it is correct for the class. The 69 Chevelle is my chosen combination to be the companion car to the 69 Camaro Kevin Cradduck and I have campaigned since 2007. The only engine we couldn't share between cars is the ZL-1 we have. So, yeah, I'm hoping fervently that a cast iron head L-72 gets rounded DOWN to 8.00 instesd of up to 8.50, because I'd like to be able to run AA with either transmission. I'd much rather be able to run A or AA with both transmissions.

Re: 69 Chevelle AA/SA 10.04 at 125mphat Spring Nats
 

They do not round up to half lbs. They round using the 3rd decimal point. If it was 8.494 it would be considered 8.49.

Re: 69 Chevelle AA/SA 10.04 at 125mphat Spring Nats
 

This is interesting. I have a copy of the Class Guide sheet for 1969 Chevrolet that I downloaded on 1/25/17 after the end of the year factors were added. It shows the factor to be 8.50, which is consistent with the math (3611 ship wt / 425 factor = 8.49647, rounds to 8.50). However, if you look at the same sheet on NHRA's website now, that factor is 8.49 with no indication that any change was made on the sheet. (Dates are included at the bottom of each sheet that documents changes.)

For anyone who is Excel knowledgeable, the formula for that cell was changed from (8.3*435/Q272) to (8.29*435/Q272), so a change was made.

Here is the sheet from 1/25/17. Note the document date at the bottom is 1/1/17, the same as the current sheet on the NHRA website. Sounds like politics to me.