I'm runing CMI cool colars on my 502. (Can't say I gained anything but they do look good.)

One problem - the attaching bolts ( header to head) keep backing off - especially #1 and #8.

Any ideas on the "fix"???? I'm getting tired of tightening them up.

MAV

I would try some blue loctite[#242] on the bolts, you need to clean the bolts and the holes out with cleaner for this stuff to work well

I put CMI's this Spring and read about them coming loose for a lot of people. I just checked mine after about every 2 hrs of run time for the first 10 hrs. Tightened them down the first couple times as a lot of them were a little loose. After that, they stayed tight. I think what happens is the CMI gaskets have to burn in and then the bolts get a bit loose. You may need to start with a fresh set of gaskets and bolts.
Some other people said they went to using studs/nuts to bolt up the headers.

Maverick,

Had the same problem, bought Stage 8 locking header bolts from my local speed shop. Never had to tighten again. Problem solved, they'll cost you $50.00.

If you use studs in place of the end bolts on each side, life gets lots simpler. Alignment for R&R is easy, the gasket drops in after you have the header in place, and with a crimp type locknut the ends never get loose. Just snug erverything up after the initial gasket "burn-in" and all will be well. --- Jer