[alanmay0]

Yes I believe that these are the factory nuts. I was thinking that maybe they were coming loose. How does the torque down to 20 lb work. How do I do it? Should I buy new nuts? If yes what kind?

thanks

[Mister Pontiac]

Originally Posted by alanmay0

Yes I believe that these are the factory nuts. I was thinking that maybe they were coming loose. How does the torque down to 20 lb work. How do I do it? Should I buy new nuts? If yes what kind?

thanks

With the factory “bottleneck” studs, the factory nuts simply bottom at the bottleneck, and then allow a 20lb torque to hold them tight. They are metal “cinch nuts,” so they’re only designed to be tightened and torqued down once, not to be used for adjustment.

If you want to adjust the valves as you’re describing, you will need to get a set of polylocks. Polylocks allow you to set the lash with the outer “nut,” then allow you to tighten them and lock them in place with the inner “screw” inside the nut. The screws bottom on top of the studs, allowing a solid lock down, at your self adjusted height.

Hope that helps.

[alanmay0]

OK will the polylocks work with the original size valve covers

[Mister Pontiac]

Originally Posted by alanmay0

OK will the polylocks work with the original size valve covers

Yes.

[skullbucket]

Originally Posted by alanmay0

OK will the polylocks work with the original size valve covers

He can't use polylocks with stock bottle neck studs can he?

[Mister Pontiac]

Originally Posted by skullbucket

He can't use polylocks with stock bottle neck studs can he?

He can, but will need 3/8” polylocks for the bottleneck studs.

When doing this, a situation can develop where a polylock bottoms on the bottleneck, but that’s no different than using the factory crimp nuts at that point. However, I don’t think any will bottom out, giving room for some adjustment. Either way, it’s a win over crimp nuts.

Ideally, you should replace the studs with 7/16” studs and use the 7/16” polylocks, but not necessary in a mild setup. That can also get into needing different rockers to go over the bigger studs, etc... depending on what you’re starting with. Cheaper, simple solution is to leave everything alone, and install 3/8” polylocks on the factory studs & rockers in lieu of crimp nuts.

Hope that helps.

[Kenth]

Originally Posted by Mister Pontiac

He can, but will need 3/8” polylocks for the bottleneck studs.

When doing this, a situation can develop where a polylock bottoms on the bottleneck, but that’s no different than using the factory crimp nuts at that point. However, I don’t think any will bottom out, giving room for some adjustment. Either way, it’s a win over crimp nuts.

Ideally, you should replace the studs with 7/16” studs and use the 7/16” polylocks, but not necessary in a mild setup. That can also get into needing different rockers to go over the bigger studs, etc... depending on what you’re starting with. Cheaper, simple solution is to leave everything alone, and install 3/8” polylocks on the factory studs & rockers in lieu of crimp nuts.

Hope that helps.

Pontiac never used crimp nuts from factory.
If you like you can use Chevy crimp nut for adjusting the rockers and they will work just fine.
Been using Chevy crimp nuts for adjusting rockers in my 1966 GTO for at least 15 years, that way i can use the baffles under valve covers. With polylocks the baffles wont fit.

[tailored68.........]

Originally Posted by skullbucket

He can't use polylocks with stock bottle neck studs can he?

Yes he can ! Coz i had the exact same issue with them stock nuts. !