383 Engine Mount Bolt Diameter ?

[Vermont Rock]

70 Road Runner, 383. The rubber portion of the engine mounts have a welded nut on one end but the other end has a hole that is much larger than the diameter of the bolt's shank. To me, this indicates that under the bolt's hex there would be a shoulder to fill the space or, at the least, a shim that would slide over the bolt. Mine has neither, but that could also mean that I don't have the correct bolts. Any help ? Thanks, Rocket

 

[Mick70RR]

The only thing I remember about those bolts is that the threaded end is tapered. This was done to allow the bolts to be started more easily. I think they are 7/16" UNC but not sure and there is no washer fitted under the hex on my car.

 

[Moparparts]

As mentioned they are 7/16 x 14NC thread with a unthreaded tapered end to start them. They originally used a fairly thick flat washer under the hex head to cover up the larger hole on the mount. I have original bolts and washers PM me if interested

 

[Vermont Rock]

Moparparts: I have the correct bolts as you & Mick70RR described, but you have explained the solution to my question. I'll PM you for the washers. Thanks, Rocket

 

[Vermont Rock]

Moparparts: I sent you a PM. I want to buy the extra thick washers. Please contact me. Thank you, Rocket

 

[Vermont Rock]

Moparparts: Thanks for the advice & washers. Rocket