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-   -   T-400 trans question (http://www.hotrodders.com/forum/t-400-trans-question-208540.html)

firebird1969 11-11-2011 06:29 AM

T-400 trans question
 
I have a th400 in a 1969 firebird, 3.55 rear, 25" tire. tach shows 3500rpm at 55mph. calculator says I should be at 2700rpm. trans and TQ conv are new 10/2010. 1800 stall. Any idea what might be wrong? tach and speedo are correct. thanks. also anyone do a 200r4 swap for a 69 firebird?

Rustydawg 11-11-2011 09:28 AM

Something is way off here. You say that the tach and speedo are correct, but if this is in fact a 3.55 gear, with a converter that is relatively tight, 3500 RPM is out to lunch.

A couple of things come to mind:

The tach is set to 6 cyl.

The rear gear is more like 4.56.

The trans is not shifting into 3rd gear - it remains in 2nd.

Just for reference - a long time ago I had a Datsun pickup with a 4.38 gear and it would sit at 3600 RPM at 60 MPH, this with a 25" tire.

SSedan64 11-12-2011 12:01 AM

Something's off ^^.

A 2004R will bolt in easily.
Same Crossmember.
Shorter DriveShaft with 32-Spline Yoke.
TV Cable and Brackets.
TCC Lockup Kit.

Crosley 11-12-2011 06:49 AM

Quote:

Originally Posted by SSedan64
Something's off ^^.

A 2004R will bolt in easily.
Same Crossmember.
Shorter DriveShaft with 32-Spline Yoke.
TV Cable and Brackets.
TCC Lockup Kit.


typical 200-4r has a 27 spline output shaft

SSedan64 11-13-2011 08:21 AM

Quote:

Originally Posted by Crosley
typical 200-4r has a 27 spline output shaft

:embarrass Good catch Crosley, I must have had the 400 on my mind. :drunk: why? I don't know. :D


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