M-36 options

KermitDRambler wrote: You have to use a six cylinder transmission. My parts books says 1971 258's got an M43.   Matt

I found an M43 with no bell housing, would the M36 bell housing cross over? :)


Edited by BadTad - Jun/25/2009 at 11:41am

Hmmm, interesting stuff!

The 71 is listed as 'oil' cooled.

So I'd need to get the 71's dip stick eh?

How about the torque converter - use the 71 or the 67?

Wish I had one near by to mock up with. grr

There are differences in the bells and converters, but knowing what they are helps! The M-4x series SHOULD fit an air cooled M-3x series bell. The difference is there is a large hole in the right side of the air cooled trans bell, but that won't affect operation. Torque converters should interchange also. The air cooled on has a fan made onto it, oil cooled doesn't. There's no problem with using an air cooled converter with an oil cooled trans, more cooling won't hurt! I wouldn't use an air cooled converter without the air cooled bell though. The fan would generate a lot of drag on the converter if the air has nowhere to go.

On the converters, if they fit in the front of the trans they should interchange. Make sure the diameter is the same though (not counting the fan in the measurement). In general, a smaller diameter converter has a higher stall speed (takes more rpm before it starts moving). There could be differences inside to affect stall speed, but all the stock six converters are generally around a 1500-1600 rpm stall speed, so there shouldn't be much (if any) difference. V-8s usually have a higher stall speed, more around 2000 rpm (stock).  I could be off on the stall speed... going from memory!

I don't know what the pump differences are, the oil cooled ones probably have a higher capacity pump since they would be moving more fluid.  Shouldn't be an issue, but the converter might have different splines on the inner torus, so definitely check for proper fit. There could be a difference in year model pumps also. The older ones (through 66 or 67) had a front and rear pump. Those with front pumps only may have a larger front pump. If the converter fits though, shouldn't be a problem. Ive done a little mixing and matching with the M-3x/4x, but forget the years and exact models. It's been a while!


Edited by farna - Jun/26/2009 at 9:42am

PS what flexplate should I use?

Shift linkage should be the same. Have no idea what the metal line could have run to, maybe the vent at the top of the main case? Flexplates should be the same. The fan on the torque converter doesn't look like a fan -- it looks more like a cover, or "second skin"  spaced about 1/4" away from the main housing, but doesn't cover the entire converter, just most of the "back" (curved side facing the trans). Easy to miss as a fan!