The BB chevy also gets to run an aftermarket head that appears nothing like a stock casting.

I don't think that taking off anything of the outside of the block that wasn't on an original block would be an issue , the current stink is that now that the big block chevies that run alum. heads can now use the GM performance head, which is made by Edlebrock and looks NOTHING like a stock GM head even if you paint it orange, is allowed to run it like that. The excuse by one person is the hemi has been running aftermarket heads and blocks for 15 years ... ignoring that the MP block and head allowed puts MORE weight on the nose of the car ... wink wink .... Someone has been able to doctor the ebrock head to look like a GM head ... I wonder if any of those are running where they wouldn't be allowed ???

You tree'd me ..

Move along ... nothing to see here ...

Siamese bore blocks.

I think it was the answer to the 71 Ford being capable of 550ish cubes in a non siamese bore block ??

Meatbook. What a waste of your life on that site. So much to learn here.

Are there any rear gear ratio limitations for this class?

Anyone have a link to the rules?

Thanks

From the posted rules -

"The rear axle housing must be of the same manufacturer as the car"

Does that mean a Dana 60 can be used in a 71 340 Duster?

I don’t know why you couldn’t.

Why would one want to?

About time to change your signature!!!

Did anybody notice the boosters on that carb?

Congrats Brian and Gene! You guys have been picking away at this for a long time, and it just keeps getting better.

Where did you see a picture of the carb ?

Not my sandbox, I just play in it. The BBC and Hemi issues have been around for a very long time. As a small block guy, they don’t really concern me personally. I understand the thought process of why some small block aftermarket heads are allowed, just don’t agree with it. For me, if you are going to allow an aftermarket part in, it has to be because you can’t find a useable original part. Under no circumstance should you have difficulty finding the most produce v8 head in the history of man. The small block Chevy. The next consideration should be, is an aftermarket part available to all the manufacturers. No, then you can’t allow it for one make. Recently, the Indy LA-X was approved, no one I know will run that head. There is no reason for it to be allowed. There are plenty of LA heads out there. It is by its nature a better head. It is legal, but against the spirit of the idea of the class. Also, they don’t exist. Indy stopped producing them 5+ years ago and they lost the tooling and have no intention of ever producing the head again. The result of allowing an aftermarket small block head is a performance advantage to one manufacturer that is not available to the others. That’s it. It was done to attract racers in a time of need. To be clear, I don’t care if you are out running for fun, my issue is if you contend for a record. With small blocks it should be stock castings only for record contenders. There were no “record contending” aftermarket head cars in the class. An opportunity to remove them from the small blocks was missed. Just my two cents.

Indy's website shows the LA heads for sale. First page of website under Parts Blowout Sale.

http://indyheads.com/

Yeah, that’s why I called to find out. No, none in stock, lost the tooling when the business changed hands and no, no intention of recreating the tooling and producing them. Straight from Indy.

I wasn't aware that the R blocks were allowed so yeah they will take up to a 4.22" Siamese bore with a 4.25" crank that's about 475 cubes.

So with a lightened block and 48 degree lifters and 13.5:1 I can see it being fun figuring out how to go 10's in an A body.

The biggest 'trick' is with a restricted exhaust you have to figure out how to the intake to feed the cylinders adequately all alone (without the benefit of overlap) so wide centers and big (in a SBM ) 2.15" / 1.56" valves.

With high compression and good combustion, surprisingly, the exhaust can still get out of there very quickly.

Also I learned a long time ago that under the right conditions a big motor can pull through a 'too small' port and effectively toss the 28" flow numbers right out the window in terms of HP/CFM

I might get back interested in this class again.

I think you are way over thinking getting into the ten's. Mine is a 4.07" bore, 59'*, using the stock 2.02 and 1.6 valve sizes. You just have to get the motor to not care so much about exhaling through a 1 7/8 hole on the passenger side.