There seems to be several bolt lengths mentioned for headers (3/4", 7/8", 1"), so I'm looking for the correct length for my install.

Pacesetter header flange is 3/8".
RemFlex gasket 1/8" (crush to 1/16").
'98 5.2 stock heads ?

I'm looking at the Stage 8 8915 kit (5/16"-18 x 7/8").
Is this correct?

Thanks!

 

I had a used set of Pacesetter headers that I installed a while back on my truck I had found on my local craigslist that did not come with bolts or gaskets. I found that the normal header bolts (5/16" x 18 thread) that are readily available in parts stores for MOPAR small blocks were too short (3/4" long). I ended up ordering a set directly from Pacesetter and they were 1" long and had a 3/8" hex head. They worked just fine, so 7/8" or 1" should be perfect for your needs. One thing I did was to run a 5/16" x 18 tap through each bolt hole to ensure the threads were clear all the way through the hole and blew each hole out with air after using the tap. I also used a generous coating of anti-seize on each bolt during the install.

 

I just installed my JBA's today that I had laying around for 2 years. I used 1 1/4" long grade 8 bolts with lock nut washers. If you use bolts that are longer then 1 1/4" then your gonna have issues installing them. They took me the better part of the day to install them. PITA! Good luck

 

Sounds familiar - I picked up a set of used coated JBA shorty headers for my truck well over year ago and I finally got some time to install them about a month ago. Since I already had Pacesetter headers on the truck prior to the JBA header install and had been through the prior hell of removing the stock manifolds/bolts, the swap went quick and easy.

I just went out to the garage and checked the depth of the bolt holes on the exhaust ports for the exhaust manifold/header bolts on a spare set of Magnum heads I had sitting in the corner. The depth of the holes ran between 15/16" - 1" deep.

 

So even at 7/8" max of thread available in the head, one would think a 1" bolt would be a better call, leaving 9/16" of thread engagement.
I can see how 1-1/4" would be a max length.
The 7/8" bolts will have 7/16" engagement... technically still enough I guess, since the torque spec is only 20lbft.

Stage 8 only have 7/8" and 1" options listed for small block Mopar.

 

Yes, 1" would be preferred, given the data you have. Keep in mind that the bolt holes I measured had been cleaned out with a tap and blown out with air. You results may vary unless you prep the bolt holes, too.

 

I forgot, the Pacesetter LT headers came with bolts, so I upended the box, and low and behold, a small box with header bolts.
They're 1", so 1" Stage 8 it is... for a few extra $, I may as well get the stainless steel.

Thanks for the input guys.