If I replace my engine and trans mounts with poly, is it still necessary to have the dogbone mount. I am working on installing a centrifugal supercharger on my 3400, my mounting location is interfering with the stock dogbone (same as 2.8). Im trying to come up a solution to eliminate the dogbone. Any ideas?

I wouldn't eliminate it, I can imagine it would be putting a lot of stress on the mounts and bolts which would result in failure rather quickly. Why no just relocated it and bolt or weld a bracket elsewhere?

[This message has been edited by DaytonTD (edited 04-09-2013).]

quote Originally posted by Bridgetown: If I replace my engine and trans mounts with poly, is it still necessary to have the dogbone mount. I am working on installing a centrifugal supercharger on my 3400, my mounting location is interfering with the stock dogbone (same as 2.8). Im trying to come up a solution to eliminate the dogbone. Any ideas?

It's a good part to have and you will very likely need it although relocated as I discovered by driving my car with poly interlocking mounts only at all 3 points. The rear cradle mount pad cracked in my case. A good dogbone mount will also help improve launch by reducing drivetrain rotation.

I wouldn't eliminate it with only 3 mounts (1 under the engine, 2 on the transmission). If you do want to remove it, then use 2 lower mounts on the engine side and spread them apart as far as possible so they can take the load the dogbone would have seen. The transmission mount brackets and their attachment points to the cradle are not built to withstand the whole driveline torque. The brackets will bend and the cradle will crack... been there, done that, got the t-shirt.

My LS4/F40 swap is 4 corner mounted with rubber control arm bushings w/o any dogbone and it doesn't visibly move revving the engine and barely moves when I put the torque to it.

[This message has been edited by fieroguru (edited 04-09-2013).]

even with 4 mounts you still need dog bone..... I have (2) engine mounts and (2) trans mounts 4 total mounts on series1 sc and it moved way tooo much... broke a few mounts then added dog bone and took care of problem....

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87 GT
series 1 3800sc (7.597 @88.53 1.579 60ft)
(series II swap in progress)
85GT Northstar
86GT 3800 n/a

I believe the focus of extra mounts should focus on the transmission or be very close to the tranny and engine joint, the reason being the torque center of gravity is between the inboard joints and anchoring points to either side of the front of the engine tends to cause twisting and in high output applications I'd be concerned about a-centric bellhousing loads on the transmission, keeping in mind we're not dealing with stock power loads for the OE mounting points and even higher output later stock motors have dual dogbone mounts with one usually sitting adjacent to the bellhousing.

I'm installing my torque mount at the rear of the cylinder head extended out about 2" just above the bellhousing.

[This message has been edited by Joseph Upson (edited 04-10-2013).]

I took the dog bone off my 87 but replaced it with a diagonal brace that ties the rear cylinder head to the cradle. It seemed to me that the engine should be triangulated to the sub frame. Just welded a bracket on the sub frame and put a piece of 1 x .250 bar stock. It's under a tensile pull when the engine torque is applied. Probable more bar than really needed but it really did the trick.

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woodys 427

I agree with Joseph. Plus, relocating the dogbone to the back of the engine should free up some room for your supercharger.