Exhaust stud install questions

[mike sampsel]

Four of my exhaust head studs came out during engine dismantling.
Trying to replace these empty holes with new studs.

The head holes are 23 mm deep, same length as the new stud threads.
But looks like the new studs are longer (new 51 mm).

When I “installed” my first stud, I just double nutted, dry and it got tight and won’t come out (although I’ve the collet tool for head studs which might fit).

These new studs look about 3/8 inch longer (maybe a little more) than my old ones. Does this matter?
Should I continue wrenching the stud in maybe with collet tool? Or try to pull it out and get shorter studs?

Picture of the new shiny stud.

[timmy2]

You need the shorter studs for your ‘78 thin flange exhaust. Otherwise your nuts will bottom out before getting tight.

[jons911]

My exhaust studs weren't set quite as deep as they should have, and my barrel nuts are about bottomed out. I can barely get the allen wrench on it. It's not that big of a deal for me as I switched to headers and can just use the lock nuts instead if it's an issue. However, if you're using the stock exhaust, you'll want to check how tall the studs are off the exhaust port and make sure they aren't too tall. Like Dennis said, if it's too tall the nuts may bottom out at the center of the stud, but also remember the studs go up into the barrel nut where the wrench goes and can push it out.

[john walker's workshop]

Use a thread chaser before installing new studs. They tend to bind otherwise.

[mike sampsel]

Nothing finer than expert advice with the morning coffee!
Thanks all.

Headers ...hum. ... I might if I can’t remedy this stud length.

I’ll be sure to thread chase the three other holes, this one too if I can get this stud out.
And search for shorter exhaust studs.

Ill be checking to confirm I’m screwed with my new studs height and go from there with the one I “installed” so far.

[timmy2]

Just double nut the new one and back it out. Or use the tool if you need to.
Measure one of the originals to get the right length.

[mike sampsel]

Originally Posted by timmy2

Just double nut the new one and back it out. Or use the tool if you need to.
Measure one of the originals to get the right length.

Since the only one I’ve installed does not take the acorn nut, I’m thinking I can leave it alone and use a sleeve and get it tight with the lock nut? Or am i making an error?

Originals are 37 mm and I’ll need these where the acorn nuts go.
Or use the old ones.

Double nutting the new one had no luck, might have been technique.

[mike sampsel]

Originally Posted by john walker's workshop

Use a thread chaser before installing new studs. They tend to bind otherwise.

I’m thinking of taking a stud and cut 3 or so lines, perpendicular to the length of the threads to make a chaser. if my chaser gets stuck, I’ll know it was a bad idea,