I made the following reply to a thread on the TPI Board, then thought I'd drag it over hear since more motor-heads read this forum, but read my reply and tell me what you think, am I off base here?

I only estimated the thickness of the guideplate and nuts and such.


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They sell in summit a really inexpensive combination stud remover and tap guide. All you would need is a decent tap set. I dont know how well you work with tools, but if you think you are up for the task might be worth it.
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I see some problems with doing studs this way, especially if running guideplates that need a fastener or "nutted" stud.


#1 is that the adjacent bosses may not be at the same height, nor be flat and when bolts down, could distort the guideplates and give uneven torque on the fastener.

#2 Is that there's a chance the rocker would hit the fastener before the rockers were adjusted properly...seems you may get away with it using stamped rockers, but not too sure about fullroller rockers.

I think I'd only feel good about installaing a screwin stud for a repair, unless i had the bosses machined down and at the same heighth.

Has anyone actually run guideplates without machining the bosses? Ever checked the clearance between the bottom of your rockers and the top of the stud boss?

Reason I ask is I figure a 3/8th nut is about 3/8th of an inch thick the guideplate maybe about .10th of an inch?

So that means a nut and guideplate would reduce the clearance under the rocker by about .475in..roughly a 1/2inch.

There maybe more clearance if a "nutted" stud was used, since I'm sure they're thinner (nut part) than a regular 3/8th nut would be..infact I think the rule of thumb is to machine about .4inches off the boss.

Anyway, just some things to consider.

I think I'd stick with pinning the studs if I was concerned they would pull out, or send the head in for machinework....then again, it's a good reason to buy a Mill

 

I agree with that, a friend tried one of those stud boss "spot facers" and he even used a drill press, the studs were sticking up in all different directions, guys were joking about how his heads looked like big block heads.
A mill is the only way to go for me.

Still thinking about getting that 327 from me, Mike? No one else wants it.

 

you need to remove .4 from the height od the stud boss. as far as know all the the spot faceing tools aren't very good. i mill my heads and use a drill press for a tapping fixture.

 

Machine down about 0.250" for typical (ARP, GMPP, Comp Cams) hex-collared studs (from the blueprinted location of the stud base) and add whatever the thickness of the guide plates might be if you plan to use them - usually about 0.400" total as ede stated.

You'll have to determine the blueprinted height of the studs before removing them, then indicate from the machined pads on the top side of the head perimeter to set your depth.

Obviously, a mill would be best, but with careful adjustment of alignment and depth control, your results can be just as accurate with a drill press. I've had very good success with a piloted counterbore in a drill press.

 

Tell ya what, it's such a long drive for you, and I don't reeaalllyy need another engine, if you want to make the drive, the block I have is your's for the taking.

Give me a holler and let me know.