8HP90 Install help needed

[1moretoy]

Very nice! Do you have a link to the mount you used? The Gforce website isn’t very user friendly.

Here you go.

Short/ Low Profile Polyurethane Transmission Mount | GMTM-LP

If I did it again I'd try this mount with some shims to bring it up a little. 1" will be to low for the holley cross member, but 1-1/4 would be perfect. This one is not as wide so you won't have to notch the actual mount.
GM Transmission Mount - Low - Conversion Crossmembers

The red lines are where I had to notch. The mount from conversioncrossmembers is more narrow and would probably clear the sides of the holley crossmember.

 

[AUSTA]

Hey all, I'm installing my trans and having a slight issue. As I jack up the trans into the tunnel it pushes slightly to the pass side and starts to hit the brace. Does anyone have any suggestions on how to fix? Running RMS front K member 1" forward mounts. Using holley trans crossmember and 8HP90 adapter plate. Everything fits great except this issue. You can see in the photos that when lowered it is somewhat centered. Then when I jack it up it starts shifting to the pass side.

If anyone has some suggestions I'm willing to try. I knew everything was going to smooth to be true.

View attachment 132902

View attachment 132903

I cut about 1/2 " slot out off the support then heated it red hot & closed the slot then mig welded it closed hard to do if you have the interior still in the car

 

[ItsJustMe]

Here you go.

Short/ Low Profile Polyurethane Transmission Mount | GMTM-LP

If I did it again I'd try this mount with some shims to bring it up a little. 1" will be to low for the holley cross member, but 1-1/4 would be perfect. This one is not as wide so you won't have to notch the actual mount.
GM Transmission Mount - Low - Conversion Crossmembers

The red lines are where I had to notch. The mount from conversioncrossmembers is more narrow and would probably clear the sides of the holley crossmember.

View attachment 133146

Perfect. Thanks for the help! I’m going to buy the 1 inch mount with the shims. I’ll let you know how it works out.