Re: Access to AMA Shipping Weights?
 

Billy I always try to go by the rules as written. I dont think you're hijacking anything.

Re: Access to AMA Shipping Weights?
 

As near as I can tell on the 70/1 Challenger and the Cuda, its all the big block cars(I'm not sure if the hemi got heavier as well, they were always pretty heavy)

Ironically, my previously overweight 70 RT just got more interesting and can now run H and I with some traction aiding balast.

Eric

Re: Access to AMA Shipping Weights?
 

It's a funny thing!
If you look at a Rule Book or go on-line and look at a Rule Book, the "rules" regarding aftermarket aluminum heads aren't written down anywhere.
Must be written in the Super Top Secret Tech Inspector Only Rule Book!

Re: Access to AMA Shipping Weights?
 

Billy, regarding the whole aluminum head deal, supposedly the aftermarket heads were allowed because supposedly usable production castings were getting hard to find. Considering the majority of the "allowed" heads were made in huge numbers, it seems odd to me that guys were having trouble scrounging up SB & BB Chevy castings, SB and FE Ford heads, SB & BB MoPar wedge heads, yet the guys with truly rare heads, like the 413 and 426 Max Wedge guys somehow manage to able to carry on. Just seems a bit odd. Maybe as a guy whose combination was not blessed with aftermarket heads,(or intake manifold), at least for Stock, I am somewhat skeptical .

Re: Access to AMA Shipping Weights?
 

Rory, I agree with everything that you've said. They were "allowed" WITH a 10 HP penalty over the production head.
Somehow, the Mopar heads are being treated as if the aluminum head is a different combo from the OEM head with it's own HP factor. Not the +10 HP over the OEM head that NHRA originally assigned.

Re: Access to AMA Shipping Weights?
 

I think the 1970 Hemi Cuda got changed as well. I believe AA/SA is a no go now. How one of the fastest production cars can't run the top class is a bit off. It is hard to tell all the changes unless you own 20 different combinations. I thought a 70 340 Duster could run D/SA but I see the factor is a natural F/SA now. All the 71 Charger combinations became heavier.

Paul

Re: Access to AMA Shipping Weights?
 

For Mopar racers I'm a bit surprised that 906 heads are hard to find, Larry world know as I'm sure he has quite a few of them, and I'm unaware of what head is being use on the Max Wedge cars but do know the 518 is fairly hard to come by.

Re: Access to AMA Shipping Weights?
 

Its like that for all the aftermarket heads! All have been treated as a separate combo.

Billy- What happens when the "aftermarket heads" get the HP hit? Does it effect the "stock head" HP Factor too?

Re: Access to AMA Shipping Weights?
 

I can understand your point BUT that's not the way that it was "sold" to us.

IMHO, if the aftermarket head (carrying a +10 factor) gets a HP hit then yes, it should affect the stock head.

The point of my side of this conversation is that whatever the "stock head" HP factor is, the "aftermarket head" factor should be +10!

These "aftermarket" heads were not handed out to be of any advantage other than that of access to the Racer. If the Racer chooses to take advantage of the ease of access provided by the "aftermarket" head then the Racer should be willing to accept the +10 HP/weight penalty.

Re: Access to AMA Shipping Weights?
 

Aluminum or replacement heads - Some received a 10 hp adjustment and others 5. On our 318 combo we petitioned NHRA for the 5 hp like our Chevy bros recd and we got it. Noticed some bb chevy also recd 10. Not sure the thinking with NHRA. Typo?

All the engine gurus i talk to say the aluminum head loses 15 hp apples to apples. I'm thinking untouched that is probably correct but with the better combustion chambers etc who knows.

So if an aluminum is untouched there could be a hp reduction under the then current factored rating. I know our 340 aluminum ss cant compare to the steel head factor. +17 hp difference on aluminum, not 10 or 5.