I just installed a new set of Kooks on my Vette. I ordered the
LS6 gasket, but when I put them on my FFHP LS6 heads, the gasket
blocked about 3/16" of the top of the exhaust port, so I ended up
using the gasket that came with the headers. I used ARP studs and
torqued the headers to 18 ft.lbs.
Because the stock Z06 exhaust is much easier to install on a lift,
I had a local shop finish the exhaust. When I picked up the car they
told me I have an exhaust leak and I should have used the GM gaskets.
Here is my problem.....The bottom "V" bracket was very tight and
pulled the collectors together. I think this is my problem because the
headers are "pryed" away from the heads. I think if I use the GM gasket
the problem might be worse. I am going to pull the bracket off and see
if I can get less tension on the headers and see if that works. If not,
does anyone make a thicker gasket that might seal better?

Thanks!
AXER

 

When I installed my Hooker Long Tubes, I made the same mistake by using the ones that cam with the headers. I replaced them with the stock GM Gaskets from the local chevy dealer and I've had no problems. That was close to two years ago.

Good luck,

Al

 

yup. Grab a set of stock replacements from your local GM dealer.