Transmission Adapters

[Ken Parkman]

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.

[rsalemi]

Originally Posted by Ken Parkman

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.

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!!!

[Cglrcng]

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.

[Rory McNeil]

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?

[west coast]

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.

[BRETV]

Originally Posted by west coast

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.

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




Bret Velde
2003 I/SA

[west coast]

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

[jmantle]

Originally Posted by Rory McNeil

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?

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.

[GTX JOHN]

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.

[Mark Yacavone]

Originally Posted by GTX JOHN

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.

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. ;-)