['69ragr]

Looking for some input and thoughts/experiences on drivetrain strength. I recently installed a reverse manual valve body on the TH 400 with a trans brake. Drivetrain consists of TH 400, 4400 stall Neil Chance converter, 3.5 inch alloy drive shaft 1350 yoke and u joints, Strange 9" with 28 spline pinion and 35 spline S/T axle and Richmond street gears.

I have been told by some that with a 4200# car I am asking for trouble, the tranny builder states that it will be OK with the 650hp and 680 # of torque (installing a 3000rpm chip in the MSD 2 step for the brake) that I have now. He also stated that if I upgrade the motor to 800 hp and over I will have to go to strip only axles and gears, and a 35 spline pinion. Any experiences out there and hopefully there not bad ones.

Thanks,
Deno

[60man]

Good question..I can't answer it but interested in the replys.I have been told by a few I need a trans brake and tempted to get one.....On the other hand with my signature car (800+HP) to me a trans brake would = break.. ??

[n20ta2]

I think the axles and gears may suffer after a while with the brake.The 35 spline count is great but The st series are not meant to be used with a brake especially at that weight.You may brake the street gears first though.

[mysticmissle]

I think the pinion will be the offending part. The street gears are fine for most apps. I have broken non nodulAr cases with less hp and wt. Is it a spool or a locker or ?

['69ragr]

I have a Detroit locker, and the heavy duty strange nodular unit.

[mysticmissle]

Run It the locker will be more forgiving then a spool too. It's ur decision but it's not like ur trying to put 1000 hp to an 8.2 you have good parts

[The Mighty T/A]

The street gear is certainly NOT a limitation at that or the 800hp level, same Strange Iron case but mine is 3.25 with 35 spline spool, gear lash set .008. I run Richmond Street gears to 100 nitrous passes, then change them. 3400 lbs and leaving on N2O, 1.25 60's. I have never had a gear failure (now that I said that, next time out....) so save your money. When you go to 800 and transbrake your weak link will be the axles and locker. The guys I build cars for and help out start failing lockers... well, they don't really break, they just starting "acting up" not locking at times, etc after track abuse at that level and slicks. So, just change the locker (you can sell it and break even on a new spool) and get those S/T axles out when you upgrade the power and you will be OK with everything else. One other note: at around the 800hp level you may start to burn up high gear clutches if the valve body is a converted factory unit. A Griner billet valve body is the fix!

Great car, Good luck!

[02Hawk]

You will break the tranny case. I did on my Goat runny a brake after one season. In a heavy car with out an engine plate the car will twist on launch with the brake. The flex will cause the tranny case to fail.....been there done that....Put in a SFI bell-housing...Your rear end and drive shaft should be OK at 650HP....I have 820 hp in my 541 and I have a 12 bolt with 33 spline axles ...but run a spool.....its fine.....I like the lash set at .007/.008

['69ragr]

I thought of that when redoing the tranny and had a super bell housing installed, man what a difference, and actually used a mid 60's TH 400 case from a caddy again even visually a thicker piece all over, so I should be fine.

Deno

[Goat-Racer]

Now that every other part of your drivetrain has been discussed, how about the driveshaft. Denny's told me way back that the 3.5" MMC aluminum shaft that I bought from them was not trans brake worthy/reccommended. I don't know if that was an accurate statement or not, but it's something to consider.
Is your driveshaft made from MMx material or is it 6061?

I later went with a 4" MMX shaft from Mark Williams and they said that it would take everything I could throw at it with a brake at my power level.

Curious to hear of others experiences with this. My first trans brake goes in this weekend!