Transmission compatibility

[SgtMarshal]

Is a 2001 Pontiac grand Prix gtp transmission compatible with a 2003 Chevy impala n/a

[Fivefingerdeathpunch]

Nope.

It would not be a direct swap thats for sure. Way different gear ratio's and the fact that the GTP trans has a HD diff.

[SgtMarshal]

can I tune to adjust for the different gear ratio, and if I leave the hd diff can I just put an hd axle on? are there any other problem area's?

[BillBoost37]

I'm running my car that way. See your other thread where you asked about the file etc. It's actually very easy.

Ensure that you match the converter and flex plate holes. If you want to use the GTP converter, then that's 258mm spacing. The NA motor will have a 245mm spacing flex on it, unless it's dual drilled. To get around this.. I put an L67/L32 flex on my motor.

[SgtMarshal]

We are going to use his na converter, should we find an l26 flex plate or just drill the l67 flex plate

[BillBoost37]

Hold up..

03.. is it's own crazy year. 98-02 are usually swappable then 04-08 with 03 being the year I'd stay away from.

[SgtMarshal]

What's the worse that could happen?

[Bake82]

It won't shift! They changed the park neutral switch from external to internal. And I believe you'd also need an 03 ecu to make it shift.


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[BillBoost37]

The PNP is easy to work around. I have posted that in the how to section. It's the other stuff that's a pain.

[SgtMarshal]

the car got replaced, decided not to mess with a transmission replacement. its hard to justify replacing a transmission on a car with 200,000 miles

[BillBoost37]

I replaced mine at 193K.. cost $200 done. My feeling at the time was... tough to spend that on a new car.

[lance4682]

not to hijack but will a 4t65e hd from a 2004 swap into a 99 grand prix....i have a slight feeling im asking the same question

[SgtMarshal]

no, there is a lot different between the 04+ and the older ones. Triple edges site is down other wise I would link you to his page, where he says to use www.car-part.com to see whats interchangeable.

[lance4682]

i meant a 04 monte into a grand prix...if it matters