Re: Legal Heads for SS/modified
 

Racing Head Service (RHS), used to offer a large port SBF, 20 degree cylinder head under their ProAction line. These were based on an Australian made cylinder head.

They were available with 185cc, 200cc, 215cc, 221cc and 235cc intake ports with chambers in different sizes, as low as 58cc. There still some out there for sale and they pop up in Ebay all the time. I have a new set of of the 235cc bare castings and would be a head to get approved as an alternate to the N351 head.

https://www.speedwaymotors.com/RHS-3...cc,225808.html

Re: Legal Heads for SS/modified
 

Had to change my head gaskets today. Wrapped a chain around my waist and bolted the ends to the shop floor to keep from ending up face down in the engine bay. I'd use my crane but it's out of reach right now.

Re: Legal Heads for SS/modified
 

And since the Ford's are allowed a 10deg head. Why not allow the chevy's a 14 deg pro action head?

Re: Legal Heads for SS/modified
 

For SS/CS?
The iron Pro-Action 14 degree head would be great.....if they hadn't been discontinued almost a decade ago.
Hasn't Ford stopped producing N351/352 also?

Re: Legal Heads for SS/modified
 

I think so. The article I have on the update and "new" casting run is dated 2002. I don't know how many heads they did in that run, but they are still available from Speedway and (I think) PitStopUSA. Jesel had a rail rocker kit for the N head in stock. It's the approved head for grass roots circle track racing so as long as Fords are on dirt tracks, N heads will be on the shelf somewhere.

Re: Legal Heads for SS/modified
 

Yes for SS/CS. You can still find em

Re: Legal Heads for SS/modified
 

NHRA will only approve cylinder heads available to the public.
The RHS/ProAction cast iron cylinder heads were discountinued many years ago.

How I know? I tried to get the RHS Ford cast iron head in the approved list and was rejected twice because they are were discontinued.

There are still some virgin SBC 14 degree heads out there, however, due to their demand in the Comp Eliminator Jr. Fuel classes, they are a big commodity.

There are still a large number of Ford N351 castings available because they have been banned from many circle track classes. As a matter of fact, I have two pairs of new N351 heads on the shelf and one set of fully ported bare heads also.

Re: Legal Heads for SS/modified
 

On the ported set are the intake ports raised and the floor raised from the short turn raised the same amount?

Re: Legal Heads for SS/modified
 

Hey Dale, it might not have been announced very well but the new record holder in SS/CS is Tim Sloan in a grand am with a 305. I dont know the specific heads he runs. He set the record late last year.

Re: Legal Heads for SS/modified
 

That was my observation also. Although I feel that NHRA makes exceptions on the "available to the public" premise. Some of the "accepted" aftermarket heads on the list are only available if you know somebody.