Bellhousing bolt size

[flyboy2610]

I am going to get an engine stand and get the 390 on a stand. Does anybody know what diameter and pitch the bellhousing bolts are?

[flyboy2610]

Nobody on this whole site knows what size they are?
They sure look like 3/8 coarse thread to me, and the bolts thread in just fine, but as soon as they start to compress the lock washer, there's a "click" and the bolt is suddenly loose again. Are these special bolts or something?
Somebody has got to know!

[forrestbump]

They're 3/8" diameter 18 threads per inch (course). I use grade 8 that are 3-1/2" in length so that 1" goes into my FE and 2-1/2" are for the length of the tubing spacers on my engine stand.

This set up holds a fully dressed FE on a 4 wheel engine stand.

Hope this helps.

[flyboy2610]

That's what I bought (I thought!) I just measured the bolts. 3-3/4". They came out of the 3-1/2" bin. Time for some new bolts from somewhere else.
Thanks, Forrest!

[davbell22602]

My 390 uses 7/16 x 14 grade 8. I have a may 1967 390 engine according to the date code.

[flyboy2610]

Hmmm. I may have to check the date code. I do know the engine was not original to the '68 F100 it came out of. I am pretty sure, by the vertical oil filter and the way the power steering setup was, that it is a car 390. I do know for certain it is a 390, though. I have checked the stroke.
I'll grab a 7/16" bolt and try it.
Thanks to both of you!

[davbell22602]

3/8 fits my timing cover bolt holes in grade 8.

[flyboy2610]

I bought a 7/16 coarse thread bolt. Fits perfectly. The prize goes to: davbell22602.
Thanks for all your help!

[davbell22602]

Your welcome