Pdestal mount newbie...E7's on 68 302

[my9302002]

Have a 68 Mustang and recently bought some Thumper ported E7's with pedestlal mounts from someone who went a different route.
I've researched the archives on adjusting them with shims but why does it seem opposite to me?
The instructions read:

"Turn the pedestal bolt by hand (no wrench) until the bolt is snug and the pushrod is seated in the lifter. Next, put the torque wrench on the bolt and slowly turn until it clicks. The wrench should turn between 1/2 and 1 turn. If it turns more than that you need to add a shim. (Shims are available in a kit for about $10.) If it turns less than that you need longer pushrods."

It seems so opposite to me, if you have to "turn more than 1/2 to 1 turn"
I would think you would need a longer pushrod to pick up the slack. If you turn less then this then a shim would be in order.
Help me to understand..
Thanks,
Drew
68 Mustang

 

[D.Hearne]

You'd be better off by torqueing the bolts to spec (25 ft/lbs) and cycling the engine thru two complete revolutions and watching where the rockers contact the vavle stem tips. Then make a determination as to whether or not you need different pushrods.

 

[my9302002]

Hearne,
Did you stick with the pedestal on your E7's?

 

[65ShelbyClone]

It seems so opposite to me, if you have to "turn more than 1/2 to 1 turn"
I would think you would need a longer pushrod to pick up the slack. If you turn less then this then a shim would be in order.

The idea is to get the proper amount of preload on the lifter plunger. If it takes more than one turn for the bolt to seat, then the lifter is being compressed too much. Shims raise the rocker to reduce that lifter preload. If there is not enough preload, a longer pushrod is necessary.

Pedestal rockers are, IMO, a PITA to set up. Fortunately it often needs to be done only once with hydraulic cams. If the heads are not on the car yet and you haven't already bought rockers, you might consider having a shop convert them to studs.

 

[D.Hearne]

Hearne,
Did you stick with the pedestal on your E7's?

Yes, the ones on the roller 5.0 in my Ranger are E7's with Cobra 1.7 roller rockers. Even though these heads have been milled .010, no change in pushrod length from stock. Same went with the Canfield heads on my 331. The rocker contact pattern on both was close enough that I didn't feel the need to change pushrod length.Both engines have been running at least weekly for 5-6 years now.

 

[my9302002]

Thanks guys!!
I'll stick with the pedestals since I have a set of nice new Crane roller rockers that came with the heads. I understand the concept of the preload with the turns now....The "longer pushrod needed with the less than 1/4 turn" threw me off, but I get it now.
Drew