How have the stock 4T65E and the HD trans holding up to the V8. I can get very low mileage transmissions under 100 miles local and wanted to get an idea if they're holding up, or should I build one. If so any tweaks before install on the low mileage ones. Thanks for any input, Vince

------------------
86 GT.. Lambo Doors, V8, 5sp, Blue
88 Formula.. Stock, White... Wife Ride
85 Gt Black ( soon to be orange), 2.8, 5sp
85 Black, 2.8, Auto
99 K2500 Suburban, 454, 4X4
04 Trailblazer, Green, Wife Ride
06 Hallmark 24' Enclosed Trailer, Blue

Have you seen this thread yet?

https://www.fiero.nl/forum/Forum2/HTML/086013.html

I have 73,000 km on the one behind my LS4, no transmission issues.

Cheers

quote Originally posted by TiredGXP: I have 73,000 km on the one behind my LS4, no transmission issues. Cheers

Is it a stock trans? Thanks Vince

quote Originally posted by Snapperhead: Is it a stock trans? Thanks Vince

Completely stock, except for a few programming chanages to reduce torque management and increase shift pressures. My GP GXP came from the factory with the MN7 variant. GM upgraded a few internal tranny parts for the ones that were installed behind the LS4. Here's a couple of links to GM's media info on the 4T65E-HD:

http://media.gm.com/us/powe...tics/08_4T65_MN7.xls
http://media.gm.com/us/powe.../08_4T65_M15_MN7.doc

Cheers

The LS4 V8 / 4T65eHD is a standard powertrain on new Grand Prixs and Impalas. The trans is plenty strong and can be further modified to take 1000 Horsepower. There are a few turbo 3800 Grand Prixs that have run 9 second 1/4 miles with them. I would have no worries racing with one.

------------------
87GT - 3800SC Series III engine, 3.4" Pulley, N* TB, LS1 MAF, Flotech Exhaust Autolite 104's Custom CAI 4T65eHD w. custom axles
87GT - 3.4L Turbocharged engine, modified TH125H
" I'M ON THE LOOSE WITHOUT THE JUICE "