Small Block Motor Mount Bolts

[daveh]

Hey guys,

Does anyone know what size motor mount bolts I need for my 71 Challenger 340 small block and how many?  I'd like ARP or something strong.  I know grade 8 is preferred.  I'd like stainless but I'm not sure stainless are going to be strong enough.  What are your thoughts?  Thanks

Dave

[Chryco Psycho]

Which bolts ? Mount to block or the cross bolts through the mounts either way I use grade 8 , stainless can gall the threads .

[daveh]

I want to get both sides.  The K-member and engine side.  My was just thrown together and I want to make it correct.  I hate doing things half way.  Thanks 

[Chryco Psycho]

the block bolts are 7/16" & vary in length depending on the thickness of the block ear they go through , , the factory bolts are fine thread & use a lock nut to keep them from vibrating loose .
The mount crossbolts are larger / longer , the factory bolts have a tapered end so they start easily , , I think they are 3.5" long , they may be 7/16 thread too ?