Screw-in studs for 289HP 1965-66 (screw dimension)

The best way is to take your valve covers off, and check it out. They can be 3/8" or 7/16"...need to fins out if they are (for sure) the original heads... Are you SURE they are screw in studs? Mark

My part dealer have several screw-in studs for Ford 289, but he can't tell which one for the early high power engine..

Can anyone tell me something about this ?

best, Sverker

The Hi-Po 289 and the Boss 302 were the *only* small blocks with screw-in studs. Get a new parts guy, and have him look up C3OZ-6A527-B, the original part for your engine.

I would check them out but my mustang is in another city right now.

Yes I've checked them several years ago. It's a

From memory, the screw thread is thicker at the head compared with the rocker side.

Could it be then that it's 3/8 at the head side and 7/16 at the rocker side (sorry I'm not so familiar with the american system)?

Also from memory, the total length is about 2 inches.

Does this sound right?

Thx, Sverker

Finally I was able to find some info:

The diameter at the block is 5/16" and at the rocker, 3/8".

Effective stud length is 1.75".

/Sverker