Transmission Adapters
 

From the NHRA 2025 rule book, Under Stock :
" NHRA-accepted adapter plates permitted."

Anyone know where to find the listing ?
Asking for....myself.

Re: Transmission Adapters
 

Mark,
I don't have an answer for you, but that line goes back to a min of the 2017 Rule book.


Stan

Re: Transmission Adapters
 

The rule goes back to at least the 2000 rule book, so it's been there 25 years.

Re: Transmission Adapters
 

Once upon a time, I was told that the Quicktime bellhousings qualified under the rule, but never confirmed it. Prior to the adquisition of Quicktime by Holley, you could basically put any transmission, either stick or auto, on any engine. After the acquisition by Holley, they did away with the slow movers, however, they still have a good selection available.

https://www.holley.com/brands/quick_.../bellhousings/

Re: Transmission Adapters
 

Thanks for the research, guys

The quote is from the automatic section though.

Can anyone go back to where any transmission from same manufacturer allowed?
Did it ever say it must bolt to the engine, or was that just understood?

Re: Transmission Adapters
 

With all this discussion about transmissions, and the fact I have a SBC pattern 904 case I'd like to sell, I went back and looked through the old rulebooks (missing a bunch) to understand how it has changed for both stick and auto.

- in 1988 both stick and auto were required to have same year make and model as the car.
- aftermarket stick transmissions allowed in 1989
- any model automatic from the same manufacturer with the same number of speeds allowed in 1991. Adapters prohibited
- OD gear not required and redrilling to adapt prohibited comments added sometime between 95 and 97
- NHRA accepted adapters permitted sometime between 98 and 2000
- sometime between 2010 and 2020 3 speed automatics allowed.

Interesting that aftermarket (stick) transmissions have been allowed for 36 years and it has been 34 years since a stock automatic has been required. For a few years it did specifically have rules that would say the transmission must bolt up. Now almost any transmission can be used, and with proflites the components are not from the same manufacturer anyhow.

It's also interesting how much wording about shifting and other things has been added.

So my SBC 904 case has no market and I think that Supra is no different transmission wise than any other stocker. And I think it is great to get a newer Stock Eliminator running in the conventional classes.

Re: Transmission Adapters
 

I long ago sold a SBC 904 case to an AMC 4 cyl guy who had a cracked case for $65 (IRC) but I think that market has dried up!!!

Re: Transmission Adapters
 

Yac they should be on the NHRA Accepted Products List (if there are any currently accepted), NHRAracer.com on left, under TECH heading, Accepted Products List...Scrolled the list contents and only found Stk/SS Accepted bellhousings 3 there and all GM and all were JW Transmission and all on Pg 54. No heading there for Accepted Adapters so a call to the tech department may be in order.

Or, call JW Transmission, tell them what you want to (adapt or matchup), and they certainly know how to get it added to the list.

Re: Transmission Adapters
 

Since it appears that a Toyota is allowed to use a GM automatic transmission, because supposedly, at some point some BMWs had GM transmissions, I wonder now if Fords will be allowed to use an adapter for a Turbo 200, since in the early 50s, Lincolns were available with a GM Hydramatic . Or is such a thing only allowed on vehicles that don`t exist in the Classification Guide?

Re: Transmission Adapters
 

Rory the way I see how the Toyota got a gm trans. Ford should be able to also. Ford owned jaguar for several years, jaguar's did use gm transmission for several years. This is not different then what was just approved by nhra. Ford should be able to use any GM trans, have adapters made and have them approved or bellhousing for the 200.

Re: Transmission Adapters
 

Even if NHRA would approve that, I would still run my C4's.😁




Bret Velde
2003 I/SA

Re: Transmission Adapters
 

Bret I am right there with you none of my junk makes enough power to hurt a C4. Wouldn't give it up. I don't have enough money for anything that has enough power to hurt a C4

Re: Transmission Adapters
 

Rory, you bring up an interesting point. Since Ford used the Hydramatic in some of their cars, it could be considered a corporate transmission and therefor legal in any Ford vehicle. You could also say the hydramatic as a GM corporate transmission, it should now be legal in any GM car including the sedan deliveries it was previously banned from.

Re: Transmission Adapters
 

I wish there was an accepted adapter to use a
904 behind a Big Block Mopar.

There are adapters that we use in our bracket cars
but not NHRA approved (I do not think any are for Mopars).

Boy would that save us some money.

Re: Transmission Adapters
 

John, I think you'd have a good case for this, after seeing what's already out there.
You'd have to use a flex plate spacer, along with one that would bolt up on both ends.
You'll need a pilot adapter for the added length and the small to large pilot difference.

Maybe there's a few guys here who could tell you how to get this one added to the seemingly nonexistent approved adapter list. ;-)

Re: Transmission Adapters
 

Hey YAC, open can, turn upside down?. Observe worms

Re: Transmission Adapters
 

We already run a 904 with adapter and a custom
convertor on our bracket cars.

Re: Transmission Adapters
 

You think YOU don't have enough power to break a c4? I'm lucky to have 200hp with the junk engine I'm running, lol!

(which is funny as I just had it rebuilt at the tranny shop because it was trashed, lol! (not by me or my power though)

Re: Transmission Adapters
 

I have to wonder if anyone has approached JW for a 904 ultrabell. They do list one for the 727. There isn't a generous number of pump bolts on a 904 but it has as many as a 200 and I haven't had a bell fall off of a 200.

Re: Transmission Adapters
 

A buddy in BC Canada run 9.4s in his SS/EA 427 Fairlane, with a Joels C4, and don`t recall him ever hurting it. Little more pricey than a C4 out of a Mustang from a wrecking yard though.

Re: Transmission Adapters
 

Yeah whoever said open a window a bit and feed it $100 bills until it's full isn't that far off! LOL! I just wish I started with a cleaner southern car instead of a rustbelt car I've owned and bracket raced since 1984.

Re: Transmission Adapters
 

There is supposedly one for sale locally which has nothing to do with me. Pat, now retired, was a big 904 proponent so it's possible he had some made by JW. The bolt pattern looks right, but can't say for sure.

https://www.facebook.com/marketplace...d-aebe0a0dd239

Re: Transmission Adapters
 

I do have an issue with the trans occasionally getting loose on the adapter on the trans on the 904.
It was in a 440 Roadrunner stocker that I bought. I removed it before
I got bounced back then some years ago. Probably would not make a difference
any more but I will not to care to chance it anyhow!