I know 1/4-1/2 is optimal but heres the situation. Were running 083 heads , 986 sSprings with Comp Pro Mag rockers on stock pinned studs. Problem is there are not alot of threads on the studs once the rocker is on and with poly locks I am lucky if I have 4 threads showing up. I adjusted them with motor running and so far so good with 1/2 turn, but I would feel more safe with another half. Or would that even effect anything?

 

Your pushrods are the wrong length and/or you need longer rocker studs.

 

I ended up going with stock 7.200 pushrods and the rocker studs are stock in the head.

 

Get longer rocker arm studs.

1 full turn on a typical 3/8"-24 will net you .042 preload, within spec but on the high side. IIRC GM and everyone else says .020-.060 lifter preload. Even at that, you really need about 9 threads (~3/8") to really have enough threads to transfer the load if general rules about fasteners apply here and they should.

Pro mag rockers? There are 2 sides to the center roller, one is recessed one is not. Got the right side up? The lock fits down inside there, if you are only getting 4 threads that way then you definitely need longer studs.

 

Yea I have the right side. Its so confusing. I see others use them with stock pressed in studs. It would cost another couple hundred to get the motor pulled back out, take off heads, press pins out , and have it all machined again for screw in studs. Is there another rocker out there available that would fit?

 

The valve spring installation will determine the length of pushrods required. The spring pocket could be high or low to get the correct installed height. The valve seats could be high or low to a factory cut which will change the height of the valve.

If your rocker is pushed up that high by the pushrod that there isn't enough rocker stud for the nut to grab then there's a geometry problem and/or the valve is sitting too high in the head (deep in the seat)

Check your valve train geometry as best as you can before swapping parts. Don't guess at pushrod length unless everything else is factory stock.

Are you putting the rockers on with the lifter on the base circle or on a lobe?

 

On the base circle, with lifters full 7.200 rod and the rocker on, I have about 6 threads with it just laying their. On the tipity top of the cam lift with the same setup and nothing compressed the stud it flush with the opening of the rocker arm.

I started the car and it runs good. I backed off till it ticked and then turned the nut still it stoped. I then went another 1/2 turn and then set the center lock in place.