T5 or T56 Manual Tranny questions

[Ole Greenie]

I'm thinking about swapping my Bowtie OD 700R4 level II transmission to either a T5 or T56 (maybe Tremec?) manual tranny...so I am looking for input from anyone who has experience or knowledge with instalation. Specifically, I am looking for info concerning mating to a big block with 450hp 490 torque, hydraulic clutch vs. manual clutch and mounting, pedals, shifter positioning, etc. The 700R4 OD I have is fine with only 6000 miles on it but I would like to do better than a 4 gear OD trans.

Any guidance or intel would be much appreciated!

Happy Father's Day!

[ColinOpseth]

Ole Greenie,
A T56 will handle that power if you aren't clutch dumping it all the time. The '93 M29 is rated at 400ft/lb and the '93 M28 and 94-02 are rated at 450. I have an M29 (close ratio) in my '72 Vega behind a stock '93 LT1 and make tracks in first, second, third...and fourth. It's big a no-no to power shift a T56 into overdrive.

As for reverse lockout, you can "crash" through the gate. I do it on my Vega. It isn't a really pleasant thing to do because it requires a decent amount of effort but I don't do it often so it isn't too bad.

I purchased a T56 for my '69 SWB today. Can't wait to get started on this project, too.

[Dingfodgy]

For a 5 speed behind a BB, I'd go with a Tremec TKO600. A T56 would hold up ok, but it might be money well spent to upgrade to the Viper mainshaft and steel shift forks. Since you're going to have to buy a bellhousing anyways- I'd get a steel unit from Quicktime and run a hydraulic clutch. For pedals you can simply add the third pedal to your setup or you can buy a whole new setup from Tilton or Clayton Machine ($$$).

BTW- Have you looked into the new TCI 6-speed auto trans? Pretty slick if you like the slush-boxes!

[jocko]

Quick question for ya - why do you say you'd like to do better than a 4 gear overdrive? Probably not telling you anything you don't already know, but the question caught my attention.

If you prefer manual transmissions, I understand that desire, and installed a T5 in my 66 (but I was replacing the 3-on-the-tree and needed an o/d trans).

Going from 700R4 to a 5 speed does not give you "more" o/d, it only gives you more closely spaced gearing in the trans. In other words, your 3rd gear is 1.0:1 while the T5's 4th gear is 1.0:1 - only the final gear is an o/d, so your mileage will not improve compared to the 700R4. Was just curious why you chose to word it that way.

Anyhoo - whatever your reasoning, if you enjoy a manual trans like I do, a 5-speed is a fun trans. I do agree with some of the above comments - T5 is not strong enough for a big block. Keisler sells a new RS o/d trans, available in 4,5,600 torque ratings. I had a hard time dealing with them, couldn't GIVE them my money because they'd never call or write back - but maybe you'll have better luck. But, bottom line is the TKO 600 is probably what you need. Dingfodgy raises a good point - TCI's 6-speed might be just the ticket for a 700R4 upgrade, and it would eliminate the need for all the stuff you've got to add to your truck to make it a stick. Stuff like:
bell hsg
drop the flexplate, get a flywheel
clutch/pressure plate
pilot bushing
the trans...
new or shortened driveshaft (possibly)
new driven gear to make speedo work (possible for ANY trans swap)
clutch/brake pedal assembly
clutch linkage - z-bar, pivot ball, adjusting rod, clutch fork, return spring
release bearing
Or, if you go with a hyd clutch (not a bad option when converting an original automatic trans vehicle) you can avoid the linkage, but have to install a slave cylinder and lines, etc
shifter
cut a hole in the floor

here's all the crap I needed to do to put the T5 in my truck, and it was already a stick anyway! http://67-72chevytrucks.com/vboard/s...d.php?t=482069

I guess if I had a 700R4, I'd think twice before I went to a stick - but once you decide, then GO FOR IT! And we'll all be here to help ya do it. Questions will inevitably come up in the process. Look forward to seeing what direction you go with this, should be a cool build. That TCI 6-speed auto might be looking cooler and cooler...

[68 TT]

It takes a lot of money to make a T-5 hold up to a big block and a heavy vehicle like a truck. Much more than it is worth.

At your power level a stock T-56 won't live long either. I broke two in my 98 Z/28 with just under 400 hp to the wheels.

You are much better off with a Tremec T-56 magnum with all the upgrades done to it. A 700 ft-lbs torque rating should handle anything you can throw at it and it also has a mechanical speedo output so it will work with your stock speedo as well as multiple shifter locations to fit our trucks better.

Not cheap but neither is replacing a T-56 after you break a main shaft and grenade the trans.

http://tremec.com/performance/t56m.html

http://tremectv.com/video_detail.php?mId=13742

http://www.moderndriveline.com/Techn...s_improved.htm

http://www.americanpowertrain.com/T56-Magnum.html

[68 TT]

You are pushing the high end of the capabilities they list for the level II 700R4 trans so you could easily end up with a broken $1300 trans plus a contaminated torque converter.

If you are leaning towards the 700R4 I would highly recommend stepping up to the Level III transmission with its 630 ft-lbs rating. The difference in price is minimal for the great increase in strength.

http://www.bowtieoverdrives.com/cata...m.php?ITEMID=9