Motor Mounts for W-Body 3400 swap

[nixtux]

What type of mounts should replace the torque struts (dogbone mounts?) when doing a boasted 3400?

Is there a place to order them or is it a 'make your own'?

Thanks

[gpse3400]

You can buy a solid rubber main mount from Napa Online. Also if you are running an automatic, you can get a rear mount from a 3.4 TDC, get the transmission/engine brace. It ties into the rear bosses like the pushrod brace does but it ties into the end of the transmission differential housing and has the mounting holes for the rear mount I suggested.

Also you should be running the pitch fork type torque struts, there is a way to rotate the square mount in its housing so that the solid rubber end is goes in line with engine movement. Or you can replace the mount it self with some hard poly replacements from the 3800 crowd, but you WILL have alot more vibration though the car, you may or may not like it...

Try getting the 3.4 TDC rear brace and mount, that will give you the most effect. As far as controlling wheel hop...it wil get under MUCH better control with the 3.4 mount but if you have some miles on the car you'll have to either replace or fortify the control arm mounts.

If your car does not have the '91+ subframe(has the passenger side rear corner mounting pad) and a 4T60-E the 3.4 mount set up cannot be used, but you can do everything else.

[nixtux]

Sounds pretty straight forward. I was thinking it was going to be a fab job to get it work.

I have 95' Cutlass Supreme. As soon as it moves again it's getting new suspension all the way around. Currently it doesn't have a motor or transmission in it so no sense in that.

[gpse3400]

'95, yeah you'll have that mounting pad. I suggest buying the mounts from Napa, the solid main lower 3100 mount and the 3.4 rear lower mount, and see about getting the 3.4 rear automatic mount/brace. Oh yeah one last thing the brace has a braket that it bolts to on the engine side. that bracket is bolted to the engine block by the timing cover by 2 large bolts. I gotta see if I have any pictures to show. If yu have an FSM youll see all of this in the 3.4 section.

[3100 MPFI]

This is a 3100 with the twin cam lower mount. I was test fitting it, but my 1988 does not have the subframe provisions to use it. The subframe that can use this mount was not started until 1991, and even though I do have a spare subframe from a 1996, I am not going to swap it out just to use this one bracket.

[gpse3400]

Thank you Taylor!!!!!

[3100 MPFI]

any time. I need to also get a pic of the front one, but I have not done that one yet, and I now have the 3100 in the car.

[nixtux]

So the subframe on my 95' Cutlass should be ok for the 3.4 mounts?

[3100 MPFI]

yup. All W-body subframes got the 3.4 provisions starting in 1991. Mine does not have it because it is a 1988. 1988-1990 does not have the 3.4 provisions, but the 1996 does.

I thought I had a pic of the subframe in my 1996 Grand Prix, but I can't seem to find it.

The rear mounting point is on the passenger side in the back corner, and the front mount goes straight into the front crossmember. The one in the back, I think it will have the power steering lines running next to it if you get under there and look.

[3100 MPFI]

got pics of the subframe mounting points for the twin cam for you.

This is the front of the subframe. The mount goes through the 2 holes that I circled.



This is the rear subframe mounting plate area.