6 Speed behind an old 302.

[Hensen]

Have heard that for toughness and a cheap price, some of the V6 tuning boys are putting 6 speed van /truck gearboxes behind turbo engines..........500bhp plus. Anyone know of a suitable box to go behind a carb 302 ??

[Mustanglimey]

For street use a V8 spec T5 will be fine, then a Tremec 3550/tko/tko500/tko600. 6 speed would be a T56. Whats it going in, use, street/strip, fast road etc.
There are also modded versions of the above configured to suit sucn as Hanlon, Liberty, Astro performance etc; be easier to use one of the above as bellhousings are available off the shelf.
I use a 5 speed Tremec TKO II faceplated by Liberty Gears. Standing up to quite a bit of punishment with clutch drops @5.6k on slicks...so far

Edited by Mustanglimey on Tuesday 11th August 21:41

[Slow M]

Mustanglimey said:

For street use a V8 spec T5 will be fine, then a Tremec 3550/tko/tko500/tko600. 6 speed would be a T56. Whats it going in, use, street/strip, fast road etc.
There are also modded versions of the above configured to suit sucn as Hanlon, Liberty, Astro performance etc; be easier to use one of the above as bellhousings are available off the shelf.
I use a 5 speed Tremec TKO II faceplated by Liberty Gears. Standing up to quite a bit of punishment with clutch drops @5.6k on slicks...so far

Edited by Mustanglimey on Tuesday 11th August 21:41

I agree with all the above except that a T5 will be fine. I don't like the plastic, OH, excuse me, "composite" synchro hubs that the pre-Tremec versions came with. UH, thanks then Borg Warner.
B.

[Hensen]

Been looking atspecs for the various T5's, from standard to heavy duty. Some say good, some say, carefull with off the line , especially at over 300 bhp.
Rather difficult to get a good box over here in the UK, hence my thoughts of truck boxes which are designed for lots of power and abuse day in day out, and many are plentyfull on ebay.

[Mustanglimey]

Don't know anything about truck trannys. The Tremec TKO 500 & 600 are rated @500/600ftlb which is a tough bolt in trans. You say 'off the line' the killer will be clutch dumps on sticky tires...while they are spinning you should be ok..its when they start to hook up that the weak links appear. A non hard hitting clutch will also protect it from 'shock'. The other thing is aggressive shifting which can kill synchros.
All comes down to what your application, budget will be.
Modded T5's live behind quick cars in the US but you start loosing 'nice' driveability like mine as I have no synchros in 2/3/4 but faceplates or dog rings. Gives a big window of engagement and no synchros to kill of with powershifts or high rpm but downshifting is a harsh noisey affair but its tough as old boots.
For a fast road car Id drop a tremec TKO in it.About £1800 I imagine.

[Hensen]

The cost is prohibitive, van / truck gearboxes will take more power for less than £500, sometimes much less.