C2 Transmission Install - LS1 Tranny Time

The adapter plates bolt to the LS1 using flush Allen bolts.

Then the motor mounts were bolted on and the engine dropped right onto the stands.

The 4L60E had a couple of issues. First, the driveshaft was sitting above the rear end by about an inch. The tailshaft is sure to hit the body at this point. The second issue is the tranny mount has nothing to bolt to so the round crossmember has to be modified.

A reciprocating saw was used to cut the offending section out of the crossmember. These cuts need to be as straight as possible.

One issue you will have is the water pump heater core hose bibs. These will be replaced with 90-degree inserts from Street & Performance.

Here you can see the crossmember was marked to reflect the position of the tranny mount. Then the engine and transmission were removed from the chassis. It helps not having the body on the car for this process.

A cut-off wheel was used to get the corners.

Before that can happen, the hole was cleaned up and squared off at the corners.

The plate was tacked in for a test fitting. Do not final weld it yet.