Nostang 96z

Since I broke my m6 this weekend, I have been debating on what kind of tranny to put in my car. I called Donato engineering to get a quote on how much it would cost to get my 6spd. fixed and it was ~$1900.00 with shipping to get a viper output shaft, vespel shift pads, new bearings, steel shift fork, carbon kevlar syncros, etc. rebuild. For that kind of money I feel that I should just go to an auto because my car is mostly a drag car as it is.

I am thinking about going with either a th350 or a th400 and I am trying to see what all is involved in the swap. I have heard that you can use a stock driveshaft for the th350 swap as long as you get the 9" tailhousing, can anyone confirm this? (does the longer tailhousing affect the strength of the trans?). Also, is the trans mount for the 9" tailhousing th350 different from the standard th350? I know BMR sells a th350 crossmember but can you you a stock a4 or m6 crossmember for the th350 swap? I know with the th400 you can use an m6 crossmember.

I am leaning more towards a th350 than a th400 because the th350 takes less power to turn and of the possibility of not having to get another driveshaft made for my car if I go to the th350 route (I have a 2 month old Denny's nitrous series driveshaft).

I plan to run high 9's to low tens on a 250 shot so I will need the trans to hold up to that sort of power level (~630rwhp). The car weighs in at 3500 with me in it.

Any opinions and suggeststions are appreciated.

Thanks
Matt

------------------
96 Camaro Z28 6spd., custom viper red with pearlcoat paintjob, 355 LT1 11.5-1, GTP stage 2 LT4 heads/intake, GTP-6 cam, full cage, moser 9" with 4.11's, and full suspension. Best so far after shakedown runs (hit rev limiter in the top of 3rd)...still needs tuning and suspension tweaking.
1.658 60', 11.886@116.05, 7.593@91.33 1/8 mile
Best mph 117.31
The Z under construction
92 Talon TSI 5spd. AWD Best E.T.-13.753@98.30mph
1.885 60ft.@13lbs boost--- For Sale!

Stephen 87 IROC

I don't have the exact number but the TH400 only takes 15-20 more HP to turn.

The long and short tailshaft trannys use the same rear mount position. The difference is just in the length of the tailshaft. I don't know the length of the M6 but the TH350 and 700R4 are close enough in length that the driveshaft can be used on both if using a 9" tailshaft TH350.

For the amount of power you plan on producing, don't even consider a TH350. Go right for a TH400. It's cheaper to build and will take a lot more abuse than the TH350. Some people will say to go with a powerglide. Your car is too heavy for a 2 speed tranny to be efficient. The third gear works well with a heavy car.

Also with that much power you should have a good driveshaft made from 3" x .083" steel and have all the yokes for 1350 series u-joints.

There's nothing stopping you from using a TH350. By the time it's built up to take 600+ hp it will cost much more than it would to build a similar TH400. If you produce that much HP then the power loss through the TH400 is not a factor.

------------------
Stephen's racing page
or check out the race car

87 IROC SuperPro race car
461 big block
Best ET on a time slip: 11.099
Best MPH on a time slip: 119.7
Best corrected ET: 10.983

Altitude corrected rear wheel HP: 480
Best 60 foot: 1.508
Member of the Calgary Drag Racing Association

Shon Herron

9" tailshaft on the TH350 works.
Can use stock A4 crossmember but you will need to have it modified. I just had some square tubing welded on to the tranny side of the crossmember, and popped a hole in it and mounted it.
If you are still using the stock TA set up, ie it mounts to the trans, B&M makes a conversion kit that does not require the welding, i learned that it comes with all the stuff to do it. But I am using the spohn TA so I did not need that kit and had to have the crossmember adapted.

As for the TH350 vs Th400 debate, that goes on forever. Very fast cars run them both.
I do think the 350 is lighter though if that matters to you.

------------------
Old Setup was:
94 Z28 A4(3.73)
LT4 H/I/HOT cam
1.69/12.27@108

mod313

And better still, there are some very fast cars with both big blocks and small blocks in both Stock and Super Stock that have switched to the fully prepped 200 trans.
Some to pick from are McClay or Billy Lynn. There are others who do build these trannies but best advise on who to pick is to go talk to other racers who use them. I believe Gump could likely tell you where B. Lynn is located and I'm told he is very reasonably priced as well.
There are also different low gear sets available as well. Go over them with your engine shop to see if one might be better for your application. I know the low gear in my tranny works great with my 400 but when I ran the 305/165 motor this past weekend it screamed for more first gear.
Just another idea I wanted to pass along.

[This message has been edited by mod313 (edited September 13, 2002).]

Nostang 96z

Thanks for the replies I really appreciate the info. I have talked to a couple tranny shops and explained my situation and they both recommended a th400. The setup I'm going with is a th400 with a 9" 4000-4200stall, no brake and a foward full manual valve body. I'll be leaving my 4.11 gears in but will change to a 29" tall tire on the bottle. Again thanks for the info.
Matt

------------------
96 Camaro Z28 6spd., custom viper red with pearlcoat paintjob, 355 LT1 11.5-1, GTP stage 2 LT4 heads/intake, GTP-6 cam, full cage, moser 9" with 4.11's, and full suspension. Best so far after shakedown runs (hit rev limiter in the top of 3rd)...still needs tuning and suspension tweaking.
1.658 60', 11.886@116.05, 7.593@91.33 1/8 mile
Best mph 117.31
The Z under construction
92 Talon TSI 5spd. AWD Best E.T.-13.753@98.30mph
1.885 60ft.@13lbs boost--- For Sale!

[This message has been edited by Nostang 96z (edited September 14, 2002).]