Push Rod Cup Clearance

When at full lift, how much clearance should you have between the top of your push rod cup and the bottom of the rocker arm.? Is there a perfect measurement that you shoot for? We have 0.008, seems way too tight to me.
Were running a hemi,brad block, with veney-2.500 heads.

 

I would guess you may need .050" or .075" shorter pushrods. The .008 clearance really isn't the issue, what i would worry about is if you have the adjuster threads all the way through the rocker. You loose alot of strength and adjuster/rocker life if you don't have complete thread engagement. Also, if the top of the pushrod is really close to the bottom of the rocker, it tends to limit the amount of oil that gets to the ball/cup. The other thing to think about is if you ever wanted to tune by head gasket thickness, you have no room to go thinner for more compression. If you need pushrods or adjusters, go with the Manton stuff- they are the best thing out there. Call Terry Manton and he can explain it much better than I can. My $.02, good luck...

 

i have 1-2 threads showing out the top of the locking nut,which i think is about right.i know i have full thread engagement,I'm gonna try cutting a push rod alittle shorter in the morning and see what that looks like. Thanks for your advice.

 

According to Manton you want 2 to 3 threads showing out of the bottom of the rocker to get proper push rod length.
Here is what Robin Manton sent me in an e/mail.

Using an adjustable length push rod, position the rocker arm adjuster 2-3 threads out of the bottom of the rocker arm. Then adjust the adjustable tool to the correct length with the proper valve lash.