Intake and Exhaust Flange issue
 

So after some tearing down and investigating, i have discovered i am leaking vacuum on probably all 6 cylinders.

The Header Flange is 3/8" and the Intake Flange is 36/64". They never put in a set of fabricated keepers to compensate for the difference in height of the exhaust flange, so instead of the keepers holding down both manifolds with equal pressure, they were holding down the exhaust before they could meet the intake. after a little grinding of the large step, they appear they will do the trick. i am taking a break for now, however i will keep yall in the know. my question is, has anyone encountered this problem before? is it just because the style of PaceSetters are different from others.. or?

I've never noticed a problem with it. The way you describe it, it sounds like you're worried your intake manifold seal would be more likely to go bad? I've blown out that gasket before but it was on the far outside edge of the exhaust because the rear most bolt had backed out a little. The seal for the intake was never broken. Not sure if other people have had any other experiences...

Also, I've never had a header on either of my Z's but in my experiences with other vehicles I've owned, pacesetters weren't exactly the best quality part. Yeah they're headers and they get the job done and they're reasonably priced, but it wouldn't really suprise me if the size was a little off

well im not so worried anymore. i found that the keepers were too thick for the thicker exhaust flange thats on the headers, causing the keepers to make contact with the exhaust before contacting the intake. after measurements i found out the difference was 1/8th of an inch. so basically when i tightened all the lower bolts/keepers, not a single one was pressing on the intake.. i took the 4 top bolts off and was able to just pull the intake off.. clearly not being held. the thickness of the intake is the clearance i needed between the shallow step and the head surface. so i ground the keepers to where the tolerances were correct

Yes this is common with the headers. I just ground half the thick washer down to match and everything was great and never leaked. even msas headers do that too

set of keepers for sale
 

would anyone care to purchase this extra set of custom fabricated keepers for a 3/8" flanged exhaust with stock intake?

1" keeper, 1/2" thick, 3/8" bore, 7/32" step.

also especially good for 4.0L jeeps and other combined manifold setups with headers.

asking 50$

contact me @ ghststalker6@yahoo.com or message me for telephone number.

I'm having same problem that you had with the intake leak using pacesetter headers. Glad to find this thread. I will do the same. Thanks!!

twas a set of pacesetters i was using as well.