Four speed bellhousing

[xbedbugger]

Does anyone know the size of the hole in the bell housing for a 4 speed transmission? I guess it's called the clutch housing bore. Thanks xbedbugger.

[1955 plymouth]

I have a 4 speed bellhousing off right now, I can take the measurement for you, not sure what internal diameter you are looking for, sorry about the idiocy, or lack of proper terminology... I will lok at it and see if it would be an obvious size to obtain.

[Dave72dt]

I'll take a guess he's looking for the diameter of the hole where the trans slides into the belhousing and possibly the depth of the housing from trans mounting surface to engine mounting surface.

[Dodgeb4ya]

Here is a shot of the hole that xbedbugger needs to be measured-it's a old pic of my clutch job on my 1952 1 ton. Sorry I don't have the diameter-never thought to measure it for future needs.

[Merle Coggins]

I have one sitting on the shelf in my shed and at one time I had measured it up for someone, but when I found those pictures I had only measured the bolt spacing, not the hole diameter. If noone else comes up with the measurement soon I'll try to get out there and get a measurement.

Merle

[Dave72dt]

That hole should be the same size as the input shaft brg retainer on the transmision. Are the bellhousings different between a 4 speed and 3 speed?

[Reg Evans]

The 4 speed measures approx 4 3/4" and the 3 speed measures about 4 1/8". Here's a 4 speed bellhousing from an M37.

[MBF]

The bolt pattern for the transmissions are different between the two so you can't use a 4 spd b/h on a 3 spd or vice versa. Mike

[xbedbugger]

Many thanks to all who responded. I was wondering if I could use a new process a 555 5 speed trans behind the 4 speed trans bell housing. The new process has a 5 1/16 input shaft bearing retainer. Now I know that the 4 speed bellhouseing is 4 3/4. Just wanted to keep the 38 all MOPAR. Thanks Mike

[Dave72dt]

5/16" wouldn't be very much to carve out of the bellhousing. You also need to consider input spline count, diameter and length, brg retainer diameter and length, pilot length, bore size, mounting bolt pattern, etc. Ton of stuff to consider when attempting a conversion like this, but if could be done rather simply......?