Originally posted by 12SCNDZ
PLEASE, don't tell me you used COMP guide plates! The ONLY
manufactuerer that makes bolt-onguide plates for the LT1 is
GM Performance Parts (GMPP)! If you have anything but GMPP
plates on it, it's probably what caused your failure. Any
GOOD mechanic/engine assembler knows to check the roller tip
of the rocker to see that it's centered on the valve tip. COMP
plates (or any other typical SBC plates) are wrong for these
engines, because the LT1 has .050" wider valve spacing.

How do I know this? Because I originally bought a set of COMP
plates, and quickly realized something was wrong. The roller
tips on a few rockers were only touching half of the valve
tip (side to side). You'd be surprised at how many "professionals"
don't know this! I called COMPs tech line to find out that they
don't even make plates for the LT1, because of the unique spacing.
If you tried running the engine like this, I can see how it would
break a pushrod, or a rocker stud...Because your trying to side
load both.

OK, I did a search to find out what the break in period for a
roller cam is and found the above comment. Is this correct? If so
it explains why the roller tips on my rocker are not exactly in the
center of the valve stems. They are not off by much, but not on
center.

I have run the Comp guideplates (which were sold to me by Thunder
Racing) with the Comp pro mags and chromoly pushrods for about
15,000 miles. So far nothing bad has happened. Is this something
to be concerned about? If I replace the guide plates with GMPP stuff
is there a possibility that permanent damage has been caused to the
valve tips, or the rockers, or the pushrods?

 

I have the Comp guideplates and Comp Pro Mags. No problems here. We checked the alignment, and it was correct with the Comp guideplates. That 0.050 difference is small, especially when divided between the two valves.

 

I went ahead and ordered the 14011051 guideplates and will
pull off the driver side rocker cover and install it on #1 and see
what it looks like. If all looks good then I will install the rest.

I will also take a closer look at the pushrods and the top of the
valve stems while I'm at it. I definately want to keep those parts
happy.

 

I was just searching about this same thing, and had found a picture of a guy who did a direct photo comparison of the GMPP to the Comp Guideplates. What he had a pic of was startling. The pic had the GMPP guideplate on top, with the Comp plate directly underneath. You could see the Comp plate was shorter at the opening than the GM, but the startling aspect was that the comp plate had a perfectly worn groove where the pushrod had been in continual contact with it. That sold me on the GMPP units right there.

Combination Motorsports aparrently sells some in house EX components guideplates that work too.

*edit*

Found the pic:

http://community.webshots.com/photo/...47075942zoPQSe

 

I'm going through this same problem. THIS is a thread I started a few days ago asking a similar question about rocker to valve stem placement using Comp guideplates. As you can see, my rockers were left of center using Comp guideplates. No matter what I did, I could not get a solid line across my valve stem. The problem I have is that I can't switch to GMMP plates because I'm going with AI's 3/8" pushrod instead of stock 5/16". Therefore I think I'm stuck with Comp's guideplates. Just got them and the pushrods in the mail today--hopefully, they'll match up better then the 5/16" plate and pushrod checker I used in the picture.

I've also heard of people using a dremel to slightly "widen" Comp's plates---anyone do this?

 

I'm in the same boat, and I'm comfortable with the comp gp and 3/8" pushrods. Just double check the geometry and make certain the rods are the correct length.

 

Just a side note for truedualws6. I've been trying to reply to your PM, but your mailbox is full.(don't forget to empty the sent items too...)

Dan

 

While not scientific , here is a visual comparison that I put together.

 

I finally cleaned up my mail mess. As far as the problems go,
whatever is done is done. The best thing is to immediately
replace the guideplates and drive the hell out of it.

 

While not scientific, that's a damn good visual!!! Looks like I'm sticking with the GMPP units. Thanks!!!!