Transmission Swap - How big a Job?

[Bob In Ct]

I've got an early stock Superformance with a Tremec 3550. 4th gear is 1:1 and 5th gear is 1:0.68. The jump from 4th to 5th is too big. I would like to replace the 3550 with a Tremec, with 4th being 1:1, 5th 1:0.80 and 6th being around 1:0.62.

So what's involved here? Is it worth it or should I just live with the current setup? Besides the transmission, what else would need to be replaced? Which Tremec would you guys recommend? Can Classic Concepts on Long Island do this for me? Vintage in Wallingford?

Bob

[vector1]

tr3550=10 spline, tko i believe would be 26 spline, diff clutch disc.

[Clois Harlan]

That is correct trans and clutch should be about it. But, I now see you are talking about switching to a T-56 60speed and I think there may be some other things to think about including the bell housing. However, if you go with the TKO 600 I think all you will need to change is the trans and clutch.

Clois

[Cashburn]

We can do it. Big job on an early SPF though. Needs to come out the top right? We are also a Tremec dealer now.

Are you looking for a 6 speed instead though, or just a differently geared 5?

[mikeforte]

Hi Bob,
The 3550-TKO is a 5-speed overdrive. The TKO-600 has an optional .82 overdrive that will work very nice. Your 3550 has the .68 overdrive and has the same gear ratio as the TKO-500. Both the TKO-500 & TKO-600 are direct bolt in with a change of a driveshaft yoke and the TKO-600 will need a 26-spline clutch disc.
The 6-speed is a T-56 and has 2 overdriven gears. It comes with a SB Ford bellhousing and will require a new yoke, and shorten the driveshaft.
As a Tremec Elite distributor I stock all models of the TKO-500 & TKO-600 and the T-56. I am also a service center for retail Tremec dealers, garages and end uses.
Call me will any questions. I'm offering free shipping and you would be tax free being an out of state sale.