Tremec Magnum 6 speed

[jims72]

Hey all, my 5spd starting to worry me. Weak model with many many miles. Like the gearing of the 6 speed. Couldn't find a post about this swap. Anyone try it. My concern is how much alteration to the tunnel, if any, and driveling angle change. Thanks...j

 

[Studdley]

I presume you're running a TKO?

 

[EdM]

Just completed an engine/trans, among other things, on my 73 Mach 1. I bought the trans package from Modern Driveline and they were excellent. I went with the TKO600 as my car is making 560 ft'lbs of torque. I only have 50 miles on the car but with 3.50's in the rear I am at 2000 rpm running 70 mph. The car is just cruising pretty quietly. I am sold and, frankly, do not see a need for the six speed.

 

[jims72]

Not a TKO, early T5. Guess the answer to my question is no. Thanks anyway...j

 

[mjlan]

I have not used a T56 but I think they are wider than a TKO.

I am almost positive that the tunnel would need to be modified to get it to fit and keep manageable drive line angles with the stock engine mount setup.

What kind of power are you making?

Nothing shifts like a T5 (IMO very nicely!), and the TKO is somewhat notchy.

If you aren't making more than 400 ft-lbs and/ or racing with slicks a World Class T5 should be ok I would think.

 

[TommyK]

Here is an old article on the subject. You may not be able to view the whole thing.

https://www.fordmuscle.com/archives/2005/03/T56Swap/

 

[jims72]

Good article, thanks.

Ron Morris has adjustable motor mounts and cross member that's suppose to make the t56 fit first gen stangs. I have a stock 84 5.0/t5 and 3.70 rear in the 72 now. With well over 180k miles on them. Freeway cruz is fine, but don't like the spread between 5th and 4th on the down shift when passing or riding the foot hills/mountains. .80-.63 fifth and sixth seem to solve that, on paper anyway. Haven't been able to find anyone who has actually done this swap and since it'll probably take the best part of $6k to do, the TKO at $2600 makes better sense. Some day I'd like to get the Cleveland going again too. What are the rates on home refi?

Anyway, appreciate all the responses, thanks....j

 

[TommyK]

Good article, thanks.

Freeway cruz is fine, but don't like the spread between 5th and 4th on the down shift when passing or riding the foot hills/mountains.                                              

Anyway, appreciate all the responses, thanks....j

My opinion is that this is more a function of the torque curve (or lack thereof) of the 5.0. The extra gear will certainly be useful with the current engine but if you are contemplating the upgrade to a stroked cleveland (and the ensuing increase in torque throughout the rpm range) then the extra gear will most likely not be needed. I recently drove a friends 1963 Fairlane with a 489 C.I. FE. It has a T56 and to me the extra gear was distracting. I have also driven a Comet with a 408 windsor and a G Force 5 speed and it pulled like a mother in every gear. However nothing wrong with the 6 speed if that is what you want I am just pointing out that with a power upgrade it may not be necessary.

 

[Don C]

Thanks for verifying what my thoughts were about it. With a broad flat torque curve as many closely spaced gears aren't needed as on a peaky motor with a narrow power band.

That said , though, nothing sounds better than an engine with a close ratio box going through the gears.

 

[jims72]

I agree it's all about torque, traction would be a problem with a Cleveland and a close ratio 6sd/4.30 rear end and a 27" tire. On the other hand a sbf with 300 lbs torque and that setup might give that 408 Cleveland a race. The t56 seems perfect for a high winding modular. But I'm rambling. This car will be strictly street. The t5 cruses at 2k in fifth, then down shifting ups it to 3k plus, seems excessive. But maybe that .80 extra gear wouldn't be enough and I'd end up at the 1.0 and 3k plus after all. Anyway you've given me something to think about.

Thanks...j

 

[EdM]

Precisely why I went with the five speed. When in fifth and running 60 or 70 a downshift to fourth and away we go. In fact, it pulls pretty well when in fifth.

 

[Don C]

It should pull well, around 550 ft-lbs must feel pretty good.

 

[je72]

Thanks for verifying what my thoughts were about it. With a broad flat torque curve as many closely spaced gears aren't needed as on a peaky motor with a narrow power band.

That said , though, nothing sounds better than an engine with a close ratio box going through the gears.

So has anyone done the t56 magnum swap yet?