[BAN]

Hey Guys,


1971 T-37. Had a 350sbc and th350 when i picked it up. I built a 400 and an m22 for it. Currently in the process of building my own headers from Scratch. Passenger side complete, Working on the Drivers side right now.

The car had some home fabbed 350sbc engine mounts that i removed. I got some Pontiac specific frame stands for what i was told, 68-72 GTO/Lemans, cleaned them up and bolted them in

I'm using the newer Butler poly locking engine mounts.
I don't know why it took so long but only today i noticed this.

The passenger side engine mount falls all the way to the crossmember. The drivers side will stay supported in the top of the engine mount. I'm not sure if the passenger side frame mount is possibly clapped out and not holding the engine up off the cross member correctly.

Can these Mounts wear out to the point that they will not hold the engine throughbolt up high. I tried removing the bolt, lifting the engine and putting the throughbolt through and tightening. The second i relive the engine crane, the engine falls back to the cross member and its sitting hard on the mount.

Anyone ever seen this?

Is the mount worn?

Pretty sure i can fix it by just welding some flat stock into the mount to hold the bolt in the correct position. Think that would be acceptable ?

Passenger side sitting hard on the frame. Will not hold at the top of engine mount.


Drivers side. Looks correct and sits high up in the Framestand/Frame to motor mount.


Appreciate the help
Thanks Guys.
Cheers
Sam

['ol Pinion head]

'64-69 Pontiac V8 A body's along with with '70-72 350 & 400 Pontiac A-body's all used the same style frame brackets. The passenger side bracket is not stamped so the through bolt area sets as high on the passenger side, thus the bolt head of the through bolt wiill set much closer to the frame. If the motor mounts are new, and you are worried about the clearance issues (often will see it at the bottom of the fanshroud) there may be some frame cradle sag and the way to get that mount up a little is to lift the engine up & go through the PITA to remove the pass side frame bracket. Once removed, you can take the frame bracket, lay it out on some plate steel and trace the outline and then cut out a spacer and then locate the 3 holes. Have gone this route several times with scrap steel that is very close to 1/8" thick.

On another customers high mile GTO, it had extreme frame cradle sag, and after the front frame had been chained down and jacked several times at local frame shop in order to keep some assemblance of an alignment, it seldom kept that alignment. The decision was then made to pull the original frame, remove the LH rear frame rail past the weld seam under the rear wheel well seam, then transfer that section into a low mile '70 donor frame, then the donor frame was blasted, painted & with new front springs, rebuilt front arms, & new lines, was reassembled. Have another one these deals going this Spring. Not only did the particular GTO have extreme cradle sag, but the GTO was wrecked in the front end several years ago as owner tried to live the "driver life" with it. The car will live again, but not to do battle in every day driving.

[BAN]

Wow, awesome information. Thank you!! I never heard of the cradle sag you mention but it makes total sense over time.

i would be happy running as is, yet the mount itself is sitting on the frame, If i spaced the Framestand even 1/8 i feel like the throughbolt and mount itself would still sit on the frame/crossmember.

I have a Canton oil pan and when the engine sits like this, the pan is close to, or actually touching the crossmember on this side. If i lift it with the engine hoist where the throughbolt is situated at the highest point of the framestand. I have good clearance on the pan to crossmember and everything looks square.

What do you mean by the drivers side being stamped. Does it have a better shape to hold the bolt in the highest point of the framestand?

To achieve this, i would have to weld a small length of steel into the framestand to hold the throughbolt at its highest location.

Do you think i could get away with this? As is, i feel like the engine will rattle around against the cross member and defeat the purpose of the rubber in the engine mount.

Again, thanks for the help, and insight. Appreciated!

Cheers
Sam

[lust4speed]

I'd be more inclined to say that's pretty much how they fit. If you look at the frame brackets, they are made differently and the left side mount is taller, and when the motor mount bottoms out on the frame mount on the left side it sits away from the frame. The right side engine mount is shorter and most mounts I've seen are just about touching the cross-member the same as yours. It can't really drop any lower because at this point the mount is sitting on the top of the frame mount. I think the poly mounts have a little more meat in the area around the bolt which makes the mount look even lower. Take a level and check your radiator support, and then lay the level across the valve covers and they might be even.

The poly mounts don't like heat so leave as much room as you can between header tubes and the mount if possible. we had one that melted some at a close spot. The black poly turns kind of brown and squishy (great technical term ) when it gets too hot.

[chrisp]

Weld a steel tube inside the perch to accept & keep the bolt up high .