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-   -   66 3 speed and 4 speed questions (https://forums.maxperformanceinc.com/forums/showthread.php?t=736393)

cfd2bc 09-05-2013 12:01 PM

66 3 speed and 4 speed questions
 
Hello all...I have a 66 Lemans with a Pont 350 and TH350 with 3.36 rear. I want to put a 4 speed in mine.

I bought another 66 with a factory 3 speed, 326 so all of the parts are there to convert mine to a manual. The questions I have are:
will the flywheel transfer to mine?
same bellhousing for a 3 speed and 4 speed?
will I have to change my rear end ratio?

Thanks!

Jeff

428goat 09-05-2013 02:06 PM

I would think you would be good to go.

Singleton 09-05-2013 02:37 PM

The Bellhousing should have holes for both the 3 and 4 speed. The flywheel register hole for the crank may not work, there are two different sizes.
Which 3 speed trans is it? The HD dearborn, (ford), or the standard light duty 3 speed?
If its the Dearborn, the output splines are different than a muncie 4 speed. Would have to change the slip yoke if thats the case.

Andre 09-05-2013 03:08 PM

With the 4 speed you will continue to use your driveshaft and and yoke that you have on the TH350, and it will NOT require any modification. The crossmember wont move, and you won't have to fool with the parking brake cables etc.

geeteeohguy 09-05-2013 03:41 PM

Very easy conversion. Your rear end ratio is perfect for a stickshift car. 3 speeds, 4 speeds, and the TH350 all have the same 1:1 final drive ratio, so the only change you'll notice is slight lower rpm's on the highway due to no torque converter slippage.

b-man 09-05-2013 04:58 PM

Flywheel register will not be an issue, it will swap.

cfd2bc 09-05-2013 06:33 PM

Thanks so much for all of the replies! Sounds like I'm good to go.

b-man 09-05-2013 06:56 PM

Just make sure the 350 crankshaft is drilled for a pilot bearing, some auto trans crankshafts won't accomodate one.

cfd2bc 09-07-2013 07:07 PM

I should be able to tell that by the block code correct? "W" is manual? "Y" is auto?

67gtospud 09-07-2013 07:14 PM

Quote:

Originally Posted by cfd2bc (Post 5015799)
I should be able to tell that by the block code correct? "W" is manual? "Y" is auto?

I don't think think this is true. I have a y coded block that had a pilot bushing

cfd2bc 09-07-2013 08:26 PM

Ah ok. I guess I'll have to just pull her apart and take a look. Thanks.


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