I'll be putting the LT4 HOT in my L98, I'll need the valve guides milled down right? Do I have to pull my heads for this so the valves can be removed?

With the new springs I'm getting, how do I know if I need shims for it?

 

besides haveing to remove the valves it's real hard to find a mill with a table big enough to park your car on to mill the guides

 

Its not really that hard to find a mill large enough. There are a few around here with 60 foot tables, and the operator rides along in a cab with the cutter. The real PITA is indicating in the whole vehicle for a true cut, and fishing the valves back through the guides when you're finished.

Another alternative is to use the Comp Cams valve guide cutter and arbor in a ½" drill, but you would still have to remove the heads and valves. Pull the 17 bolts and remove the heads, man. Recut the spring seats and replace the "pull-out" rocker studs while you're at it. You might as well do it all at once. Use seat cups if you need to, but the seats will then be machined for whatever size springs you'll ever want.

 

I've heard the aluminum L98 came with screw in studs from the factory, is that true?

 

UT,

That could be true with aluminums, and it's easy enough to check.

 

How do you check Vader? I haven't done much engine work before and I'm not picking this engine up til tomorrow so I'm not familiar with it.

Also, what's the max lift I can go without milling the guides?

 

My heads are at the machine shop, I am putting in the comp cams 8-502-8 218,224 490 503 on a 112, they called me today and said my guides would need to be milled. They said they only had about 480.

nick

 

The max lift you can go is entirely dependant on the heads, they vary too much to say a specific number IMO.

The vette AL heads all have screw in rocker studs.

 

89Blue, what are they charging you just to have the guides milled?

 

oops, double post

 

just an update. took the heads in yesterday, guy at the shop said .050" off the guides will be plenty for .492 lift.