engine stand bolts for nailhead

I'm trying to get a 425 on an engine stand, the 3/8 bolts are a bit too small in diameter. anyone know what size I need? this will be my 4th trip to the hardware store...

 

7/ 16ths maybe? Be sure to buy grade 8. Next is 1/2

 

7/16ths does it for the benefit of future searchers. I've read a million threads on gr5 and gr8 on engine stands. I'm not telling anyone which way I went.

 

Summit sells a full set of engine stand/bellhousing bolts in all gringo sizes for all gringo engines (that use NON-metric threads). Cost is nominal, considering how much money you're hanging on the end of that stand.

dj

 

The bolts you need are 7/16-14.

 

and they don't have to be grade eight...a single 7/16 bolt will hold the engine's weight, so four will work even if they are hardware store grade.
don't bother telling me they won't, they are holding a 401 Nailhead in my garage right now.