I know the two are practically identical except for a few minor diffs...how long did your built tranny last behind a 375+ HP car? I plan on using a T-56 behind my 350 and am expecting over 400 HP. Mods are ZZ9 cam, ported edelbrock TPI base and SLP runners, 58mm TB, TRW forged pistons, u-pulleys, custom chip, TFS 23* heads, SLP 1 3/4 runners, borla catback and new cat, 1.5 roller rocker arms, 3.73 gears, MSD, alot of little mods and 30# injectors. Soon a Superram. I have a fresh tranny rebuilt with a hard 1-2 and 2-3 manual upshift, kevlar friction material, servo, shift kit and want to use it in the meantime, I cannot find any good LT1 T-56's. I'm wondering what usually breaks on a high-po 700-R4, input shaft (30 spline), other internal parts or friction material burning up. This is an '89 unit and has high-quality parts in it. I'm mostly scared about what happens when I hit the 150 HP nitrous on a 420-some HP motor. Someone gimme an idea! The converter is a 2000-2200 stall unit, new aftermarket flexplate.

Should I worry more about the tranny or the 3rdgen 1LE aluminum driveshaft (new U-joints)? I was thinking up upgrading to a 4thgen shaft. Tires are p275-40ZR17's. Thanks!

[This message has been edited by dhirocz (edited September 08, 2001).]

 

When you say Shift Kit do you mean a Genuine TransGo or an inferior product? If you have the TransGo Shift Kit it will help allot but you may be better off with your combo to upgrade to the TransGo Reprogramming Kit. As far as internals go, the Frictions, Input Sprag, Sun Shell and Geartrain all have their weaknesses. I would probably be most worried about the converter holding up under the Nitrous shot than anything else (again, IF it is the TransGo kit).

 

It's a transgo...no BS B&M later. I didn't like that stuff too much...the shifter was alright, though.