Thread: More Trans swap questions

I have a 99 gt I'm putting a different trans in... I heard 97 to 98 have threaded cooler lines... Mine has threaded cooler lines... And I was told the old owner put in an hd diff... Should I look for a hd trans or regular 4t65e? Will an 02 century trans work? (4t65e) and than change gear ratio in th pcm?

Sent from my SPH-D710 using Tapatalk

Ok. If the century does have a 4t65. Can I install it and just have a guy change the gearing in he pcm to the 3.09 or what ever the century ratio is and do I quick run to see what it looks like?

Sent from my SPH-D710 using Tapatalk

Originally Posted by BillBoost37

Check that the century has a 4T65E, IIRC most got the 4T60E for quite a bit longer because they were 3.1L cars vs the 3800 cars.

If your Diff was swapped that means you are currently running a 3.29 gear ratio. Any non HD 4T65E transmission plus that diff will give you 3.29 ratio. If you dropped in the HD trans and reprogrammed for 2.93, you are likely to need to tweak your timing and shift tables as well.

You are correct Bill. The Century did have the 4T60 but as of at least 2000 m.y. they were 4T65 cars.