Now to the motor mount design and fab. When we first test fit the engine and tranny we could see that the OEM cast aluminum motor mounts sat right on top the frame.

OEM motormounts.

Looking online I found Speedway's #7209314 universal bolt through engine mount cushions.


The upper portion from the large washer up to the mount (the part that would be above the frame) was 3/4", so we clamped a piece of 3/4" mdf on top each frame rail under the mounts for dummy purposes. Supporting the tranny with a floor jack and jacking it up just below the cab floor and checking the front damper with a magnetic protractor gave an engine angle of ~3.5*. adjusting the engine fore aft with the radiator mount/radiator clamped in place we found placing the mounts just behind the shock struts gave us the clearances around the engine we were looking for. I've already documented the header fit issues that dictated the shifting of the engine 1" off center to the passenger side. With all the mount locations established I turned to the computer to design the frame supports for the biscuits. The large washers the biscuits sit on are 3" OD, so my first thought was using sections of 3" OD EMT conduit since I knew the recycle yard had a large supply of that size EMT. But as I got into the full scale cad drawings I realized there were going to be a number of difficult to solve different conflicts with the shock rod mounting bolts on each side. I took a trip to the recycle yard to see what choices I might have, and found a stack of 4' long 3.5" OD 1/8" wall DOM tubing sections. I bought a section as well as a 4' long section of the 3" EMT (just in case) for $7.00. and started to revise my drawings using the 3.5" tubing. The 3.5" tubing worked perfectly on both sides and would allow the shock strut mounting bolts to be used to bolt the mount supports to the frame, just needed to cut two 3.5" washers. Since a portion of each tube would not sit directly on the frame, I decided to cut arched top "windows" into the side of the tubes to access the mount bolts and the shock strut nuts. The passenger side tube would be split vertically and welded to an 1/8" plate to fit inside the frame since the vertical flange of the frame was just 1" from the center of the 3.5" disk. The driver's side had to be fabricated differently, since most of the 3.5" disk including the mount bolt would be inboard of the inside frame edge.
to be continued...

 

driver's side mount drawing.

On the driver's side the entire piece of tube minus the arched window would be used, the top plate, rather than being a round washer would be 1/2 disk with a rectangular extension that will be bolted to the top of the frame. Two welded on rectangular plates would connect the tube to the platethat fits against the inside of the frame and is again bolted in with the shock strut bolts.
I need to take more pictures of the mounts this weekend, but here is a shot of the test fitting the driver's side mount.


test fitting the driver's side mount, frame has not yet been drilled for the two top bolts

 

AX, I appreciate the details of your help guides - keep up the good work.

Tom

.

 

You got it Phil. The top bolts on the gusset plates only need to be loosened, and they will swing out of the way, don't need to be removed. Will make it easier to re-install. slide in horizontal member, put in the two tab bolts, swing up gusset plates, install bolts, Tighten and set tranny onto mount plate. The OEM tranny mount bolts to tranny with single bolt in center which can be removed through larger hole in crossmember plate if preferred.