5.3L into 89 s-10


New Member
Jan 20, 2006
I was wondering if anyone knows what has to be done to use a th350 trans with a 1999 5.3L? Also... does anyone know if the engine wiring harness from a 5.3L controls the 4L60E transmission or does it have a seperate control module?


Veteran Member
Lifetime Gold Member
Dec 8, 2000
Republic of Texas
To use a Th350 trans you need a flexplate, adapter, and bolts used to put the 4L80E behind a 6.0L.

I don't have the PNs handy or I would post.

The PCM electronics control the trans. Same controller for the motor, they are not seperate.