Thake618

In an effort to educate myself on the lt1 valve train upgrades i am looking at i still dont know if i understand the use for guide plates, its in the name i get it but how do you set them up? do you need them? does it hurt performance in the long term? i cant seem to find a ton of information on installation and setup for the lt1.....ISKY plates to be exact.

What am i grinding off to fit? i did read about that. lol im getting there.....that seems to be my last hurdle to tackle before the engine is removed

DrewHMS97SS

I am not aware of any grinding. They mount below the rocker studs. The purpose is to keep the push rods aligned in higher performance engines. I couldn't find anything easy to reference, but I would suggest contacting ISKY if that is the brand you plan to use and have a conversation.

Here is how they install:

Thake618

the iskys are adjustable I believe 2 piece bind ends to fit to the tolerance and weld them. If they make a diffrent one be please do tell

Chimera96

Guide plates are used to keep NSA rockers on the valve tip. Considered better than using SA (self-aligning) rockers in RPM's above 5500

The ISKY are in 2 halves which allows them to be "spread out" in cases, especially on LT1 heads you need to get each RR dead nuts centered L-R on the valve tip

You may find that you need to move the 2 halves closer together than they can as is so you "grind" off the ends of the fingers of each 1/2 until they merge close enough together to align a particular RR center on the valve tip

One piece guide plates, especially on LT1 heads do not allow each RR individually to be lined up. When you move them both intake & exhaust RR are affected equally meaning that you get one right and the other is...well close.

You start by just centering them under the RR studs where the studs are just tight enough you can move them independent of each other until you get both RR per cyl dead centered L-R on the valve tip. If one particular cyl requires the 2 halves to be closer than they go that is when you need to remove that one and grind the ends of the fingers off so they can merge closer together (talking about the ISKY adjustable)

Once each RR is centered you TQ the RR stud to spec. I did not spot weld the 2 halves of the guide plates together

alex-z28

Thanks a lot that explains it well. I am looking at cam swap and I was wondering myself what was the exact purpose of the guide plates. The rockers I was looking at are Lunati self aligning 1.6rr, so can I use guide plates for these rockers as well even though the are SA for added protection or not or just get guide plates and NSA rr. I was not planning going higher then 6100 rpm do to stock bottom end.

lt1-xjs

You do not use guide plates with S/A rockers.

Chimera96

Alex ^^^^^^ THIS