HARRISONMIRAGE

I just bought a set of pro magnum roller rockers and I have two problems.The first is that they don't clear the valve cover wich I think I can fix buy machining the retainers a bit shorter.The secon is the roller tip doesn't center up on the valve tip.The edge of the roller is equal with the chamfer on the valve tip.The heads are new gm aluminums of a zz crate motor(same as edelbrocks).I have long slot GM rocker that came with the motor that I am leaning towards using.What do you guys think.The cam is the stock zz cam with aprox. .550 lift.

blue thunder

I just got done installing a set of pro magnums on a 454cid, edelbrock heads and had no problems. What do you mean by valve tip chamfer? On the surface your problem sounds like push rod length.

Dave

TomR

What valve covers, and what do you mean by machining the retainers???
Is your motor a GenIV,V,or VI?? What length Push rods? What lifters are you using??

tmdog

Woudn't tall valve covers solve the problem. They did for me.

Crazyhorse

The valve alignment issue is fairly common. You may have to split the pushrod guide plates to get the rockers aligned on the valve properly. otherwise I understand Competition Cams makes guide plates that are closer than the GM originals for alignment.

HARRISONMIRAGE

Crazyhorse,I think I could get the side to side allignment to an acceptable point by moving the guide plates,maybe file the holes to allow a bit of side to side adjustment.Tom the motor is a gen VI zz502, and by machine the retainers I meant shorten the nuts.They are about 1 inch long now with a set screw lock that buts up against the end of the stud.the valve covers are the GM ones that use the rubber gasket that is about .125 thick.I could double up the gasket as well.Dave the problem is not the roller running off front to back but side ways allignment(controled by guide plate).

mcollinstn

Split the guide plates. You can slot them if both of the pair need shifted the same direction, but that is usually NOT the case.

You can shorten the locks, as long as there is no interference with the top of the rocker on the hex.

You mat also find interference with the drippers on the valve covers. Most grind them off, but I like to leave as much as you can.

Crazyhorse

My genV covers fit over my Crane gold rockers on my Merlin rectangular-port heads and I can still use the stock GenV o-ring. But Dyno has the Merlin oval-port heads and he had to use extra-thick MkIV cover gaskets to clear his rockers.
I'm with mcollinstn. Split the guide plates.

HARRISONMIRAGE

When you split the guide plates do you tack them back together after you get them in position that you want.These valve covers I have are dimensionally the same as gen V but they use a thick rubber metal core gasket similar to a gen V/VI pan gasket.They have a spot cast in them for a tin 502 decal.They look pretty cool so I want to use them.

mcollinstn

People usually just tighten the stud down on them once they are where they want them. If you got a welder handy, then by ALL MEANS tack them back together (just remember that if you lay a good bead on them to start, that they will pull back together - tack 3 little blobs, one at a time, then run a bead in 2 pieces).