Paul Bell

iTrader: (9)

I have in my shop two Select Performance worked 4L60E transmissions. One is out of my ‘94 Firebird, the other from my ‘99 GMC Savana.

The ‘94 unit is the original housing. The ‘99 is the newer LS style housing.

I’d like to install the ‘99 van unit into my ‘99 LS1 Firebird.

I need to swap tail housings and output shafts. The tail housing looks pretty straightforward but I have no clue how to do the shaft. Do I need to do internal disassembly or need special tools?

Paul Bell

iTrader: (9)

Ah-HA! Upon closer inspection, the ‘99 tail housing is longer because the main housing is shorter. Bell housing to output shaft end they are the same length. And you are correct, the tail housings are completely different and will not interchange.

To do this swap, I simply need to use the tail housing from the unit I’ll be removing from the ‘99 Firebird as it has the torque arm and exhaust mounting attachment points.

This will be easier than I thought.

No, the ‘99 van was a small block, they got the LS series engines starting in ‘03.

Paul Bell

iTrader: (9)

This is the unit from the ‘99 van with the small block. It’s a LS style transmission with removable bell housing.

This is the one I’d like to put in the ‘99 Firebird with the LS1 engine.

I’m thinking (hoping) that all I need to do is swap in the tail housing from the Firebird as it has the through-holes for the torque arm mount and exhaust hanger (although the torque arm is on it’s own crossmember, not the transmission).

Of course, I will be using the torque converter from the Firebird LS1.

Thanks Bro!

Paul Bell

iTrader: (9)

Looks like I'm not doing this swap. While the '99 Firebird has a high milage stock tranny, both units on the floor are upgraded to 4L65E specs with all hardened shafts, thicker drums, hardened shafts, more clutchs, etc.

I'm gonna be selling the one from the '94.