The Stovebolt Site Forums The Shop Area The HiPo Shop offenhauser intake on stock exhaust manifold for 292

I had a little time to replace the exhaust gasket and fix a leak this past weekend so I decided it would be a good time to install an offenhauser manifold that was given to me along with a Holly 390 cfm 4 bbl carb. It was all going well until I found that the two studs that connect the exhaust manifold to the intake manifold were about 1/2" too long and interfered with the intake manifold. I found very quickly that vice grips were not going to remove the studs without help from a torch. It seems that the easiest solution would be to run a die down the studs to get more threads and use a cut-off wheel to remove the extra 1/2". I'm reluctant to do this because the studs will now be too short for the stock intake if I run into a problem and need to change back. Is this a common problem when making this change? Is there a better solution to solve the stud length? Thanks for any suggestions.

It seems like your saying that the studs have an unthread section up against the manifold. This is common when the stud has two different thread pitches. If so, I would think you would remove the offending studs and replace with the correct length and pitch that mates to the manifold. Nuts to match the thread pitch would be no problem and who is going to know.
I would try to remove the old studs with two nuts (jam nut) and use "Kroil" oil and be real slow by working the stud back and forth. Sheared manifold studs can make grown men weep.

Don't forget to use brass nut, also.

Ed

I used heat on the two studs and removed them without to much problem. It was easy to get heat on them due to the locations. I now use standard bolts the correct length.

Ed;

Why the brass nut?

Not Ed, but answer is corrosion. I prefer silicone bronze myself, but that's just me.

Steel nuts ' weld' themselves to the studs, frequently making them impossible to get off, especially with restricted access. Brass has enough different expansion than steel, so that never happens.

Beltfed, where is a good source for Si-bronze nuts?

Thanks,

Ed

I purchase from "McMaster-Carr" (404) 346-7000. Internet also. Example: 5/16-18 hex nut, p/n 93435A032 is around $15.00 plus shipping, several years ago, for bag of 100.

Hooah. Thanks!