[steve25]

78w72, I am shocked by what you just posted !
You really can’t see with certainty that exh rocker’s that Dennis has on his motor are very much going blue?

[steve25]

Here’s another question for consideration.

Does comp still make non roller tip stamped steel rockers for Pontiac’s?

Are the balls used with those different then the balls used with the rockers we are talking about here?

If different could there have been a mix up at times

[78w72]

steve, sorry for any confusion or misunderstanding, my reply was quoting the pics in post #118 showing the stock rockers on a 1500 mile engine... other pics he posted weren't what I was replying to.

[steve25]

Oh. Gotta ya now, thanks!

[Baba O'Riley]

And now, back to the troublemaker who started all this.

To keep the rocker for cylinder #6 from slipping off my ‘71 400 with #96 heads, I’m switching to ARP rocker studs and Perma-Loc nuts, keeping the stock stamped rocker arms and balls. Previous threads recommended using their 134-7103 studs for 400s, which have a 7/16-20 upper thread that’s .670 long from the top of the stud, with a .700 screw-in depth and 2.47 total length. Like the stock studs, the ARP’s have a shank diameter of .42".

I called ARP but they don’t have an application chart for motors per se, you have to trial-and-error it yourself to get the right rocker hardware for your motor and valve configuration.

The problem I’ve run into with these 134-7103's is the threading doesn’t drop down low enough from the top of the stud to secure the rocker. From the base of hex bolt to the bottom of the rocker arm nut threading on a stock stud is .96" but the ARP only comes down to 1.10" from the base, so the arms can’t be tightened down.

So – I’m going to try ARP’s 100-7101 studs instead – its thread extends a full inch from the top of the stud, not the .670" these 134-7103's do. With those we’ll get the valve lash set, then put in the Perma-Locs to hold them in place.

Whaddayathink?

[Formulas]

I think you should seek Paul Spotts on Ebay order his 7/16 RAIV studs and be done with it

https://www.ebay.com/itm/27678390246...mis&media=COPY

Or

https://www.ebay.com/itm/27671167420...mis&media=COPY

[steve25]

Instead of spending more money on different studs why don’t you first try adding a stack of three grade 8 7/16” washers on top of the ball before you put on the poly lock set up ?

Just note that if I recall right you can’t use USS type washers because there OD is too larger, and 2nd after doing this you need to check that the poly lock clears the valve cover .

[Kenth]

On my 1965 421 with 1970 #64 heads i´m using CBB OEM replacement rocker arm studs/nuts (Pioneer) and OEM stamped rocker arms. No issues whatsoever.

[Tandyman]

I think the 135-7101 is the best choice if you want ARP studs. The 100-7101 is extra tall and works well if you want to run stud girdles.

Glenn