Nut & bolt sizes engine mounts??

TW71 · Post by **TW71** » Sat Sep 14, 13 6:22 pm

Does any one have any information for the original nut and bolt size / length / thread type ( unc or unf ) for the engine mounts that Ma mopar used (71 b and big block) , the one's that go through the lugs on the engine block / mount ears?

It may be easier to get a fresh set , I seem to have a mixture.

Thanks!

JohnR · Post by **JohnR** » Sat Sep 14, 13 10:40 pm

From the bottom of the dark pit that is my brain 7/16 UNC X5 1/2 ins long or maybe 4 1/2 long

Cannonball · Post by **Cannonball** » Sun Sep 15, 13 6:07 pm

secerall lengths used but they are unf for sure, maybe they went unc a bit later

Pete · Post by **Pete** » Sun Sep 15, 13 7:30 pm

Every correct motor mount Bolt I have ever seen have been UNF.

They do vary according to position on the 3 holes per side....Grade 8 though from memory..........

TW71 · Post by **TW71** » Mon Sep 16, 13 10:19 am

Thank you guys, I will get some fresh ones ordered, UNF #8??

Pete you say maybe grade 8, do you think this would be the way to go with solid mounts?

JohnR · Post by **JohnR** » Mon Sep 16, 13 6:41 pm

Miss read this thought they were the ones that go in the bottom !!! yes 7/16 UNF and lock nuts , I think a couple of them are longer as the lugs are thicker , sorry if I misled anyone

TW71 · Post by **TW71** » Tue Sep 17, 13 9:47 am

Thats ok John, I was interested in that one as well so your input was helpful!

I am not sure whether its grade 8 on the engine side or 5?

TW71 · Post by **TW71** » Tue Sep 17, 13 6:22 pm