The front intake/exhaust stud is stripped on my B20F head about halfway in. Any suggestions on how to fix it? Thank you.

By halfway in, you mean that some of it is sticking out of the head?
By the way, this is NOT a headbolt, it is a manifold stud.
Headbolts are 7/16"-14 UNC. Manifold studs are 5/15"-18 UNC.
If the stud is sticking out, grab it with something and take it out and
put in another one or replace it with a hex-head bolt and washer.
--
George Downs Bartlesville, Heart of the USA!

Thank you. Sorry I confused everybody with my incorrect terminalogy. Anyway, yes the manifold stud is stripped on the outermost 1/2 inch where the nut would normally be.

I think Rhys and Ron, and George have covered this pretty well, but I'll toss in my comments as well.

I personally has to replace several manifold studs on my new B20. A quick visit to your local Ace Hardware (or equivalent) should yield you several "automotive studs." They are usually in a box in the nuts and bolts section and run between $0.80 and $1.50 each. Pick up some red loctite thread lock to help get the new stud to stay in.

When I was looking, I could only find 5/16" with coarse threads (18) on the head side and fine thread (24) on the manifold side. This is all that's easily available. I replaced all nine of mine with matched studs, but had to pick up a set of 24 pitch 5/16" nuts to match the new studs. I went with Grade 8 nuts and washers to supplement the thicker volvo washers.

BTW - I've lost a number of manifold studs between the three motors I've been working on. Only a one actualy stripped. The remainder broke off either as I tried to remove the holding nuts, or before I got the motor. Seems to be reasonably common for high milage motors...

I have a question for you. This is the type of thing i did to replace one stretched to the breaking point rocker assy. bolt. I replaced all three with corresponding size and thread count Grade 8 (golden) bolts. Are these going to be good replacements? Somewhere along the line, I talked to someone who mentioned they were expansion bolts, hence the stretching till one snapped, and that i would have to go to a machinists' specialty bolt supplier. Of course i am pretty sure this advice came from my local carpart convenience store. Are the grade 8 bolt going to be alright, or does one need bolts that will flex with the temp of the engine to maintain valve lash at high temp.
Everything seems to be fine the way it is, and i don't think those 8's are going to snap on me, I was just wondering what other people did for thier rocker arm assembly bolts.

Colin;

Don't take this wrong, but in order to get valid usable help from responders, you must try to accurately describe your condition with standard terminology...Rhys is a better man than I for being able to figure out what's going on from your description (which frankly confused the hell out of me)...just because a bolt is located at the head, doesn't make it a "head bolt". Headbolts refer to very specific bolts which hold the cylinder head onto the engine block...a stripped one of those is a minor disaster!

A manifold stud is threaded into the head, protrudes from mounting flanges of the manifolds and gets washers and nuts to hold these in place...if it stripped "halfway in" does that mean your trying to describe that its' thread is stripped halfway along its shaft (which would be down below the flange surface and wouldn't bother anything, because one could still thread on the nut)...(to repair this, remove manifolds, remove stud with stud puller or double-nut, replace), or that a manifold stud HOLE is stripped (repair by helicoil, see Rhys' post).

Cheers

Fortunately, that's the easy one to get to.
You can install a 5/16 UNC helicoil, or drill it to 5/16 and thread it with a tap for 3/8 UNC, and then use a 3/8 stud and open up the hole in the manifold flange.
Remove the manifold of course before doing either.