ok guys, I'm trying to reassemble my valvetrain, and I have few questions.

1. Should I install my guideplates while the heads are off the car or on?

2. I know I need hardened pushrods, but when I "rubbed" a stock pushrod against the seemingly harsh guideplate, it SERIOUSLY scraped up the stock pushrod, which scared me. Will it be safe (i.e. not scratch up) the hardened ones?

3. I bought a tap and the bit 7/16"-14 to clean out the head bolt holes, but the guy at sears said he has never heard of "thread chaser" and the tap should work even though he knew I didn't want to cut new threads. Was he right??

thanks!

 

TTT

come on, someone chime in...

shoebox???
injuneer??

 

1. It is easiest when the head is secured, because the torque for the stud is 50 lb. ft. Your call on whether you want to do it out of the car and can hold the head still. You should be using GM p/n 14011051 guideplates.

2. Hardened pushrods will be fine.

3. Yes, there really is a thread chaser. The Sears guy should get out more often.

 

Um...A few things here. First of all, the "threads" in the LT1 are "heli-coiled", with steel inserts, from the factory. I'm not even sure if it's safe to rechase them.

Second, you HAVE to install the plates once the heads are on, so you can align the rocker tips on the valves. All plates have some lateral movement.

Last...AND MOST IMPORTANT!. Make sure you've got the right guide plates. GMPP (GM Performance Parts) is the only manufactuerer that makes the right ones for LT1's. No COMP, Crane, or ANY OTHER will work! I'm just trying to save you some aggrivation and broken parts.

Frank

 

Should the roller be centered on the valve?

 

Yes, but you'll notice that some still aren't perfectly aligned.

Frank

 

Frank,
Does this apply to the LT4 heads too?