KULTULZ
Well-known member
The fact remains the left motor mount is broken.
When I replace the engine in my 55, I bought new MM. I drilled 5/16 holes through both metal sides and the rubber. Then I put in grade 8 bolts, tightened the nuts finger tight, then loosened them one full turn, and double nutted them. Two on each side. The reason being that back in the day, I saw many of these cars with a broken L/S motor mount, and the engine would lift on acceleration.
My 55 sedan had a Tremmec T3550, and I made a custom trans crossmember, it was up so tight, I could not get a ballistic blanket around the bell housing.
Your suggestions/modification(s) are great, especially safety strapping the left mount.
But you replaced your trans mount to accept the added length of the new trans whereas his install did not. Your application is HP, whereas his is not.
His mount(s) will remain stressed.