I installed my longtubes it was pretty easy once the factory equipment was removed. The passenger and driver both took less than one minute to slide in I was amazed how easy it SEEMED. The driver unfortunately is pushed against the a support and it will not let the gasket seat properly. I will get no seal. I tried jacking the motor lowering etc it does not want to seat. I heard someone say new motormounts help but I have the thing jacked very high and everywhere in between it will not align I can see the top of the exhast holes which will not be good. I tried trimming the a support but I am not sure how much needs to go. Did anyone with these have a similar problem. I am not sure how much needs to come off or if I should try it with the new mounts although jacking the engine seems like it should have eliminated that need. Anyone please respond soon.
JMFNX@AOL.COM
1989 GTA

 

I've had a couple sets of hedman full length headers. I also ran into a slight problem with the drivers side header hitting the crossmember but not as bad as you seem to have. One tube touched the crossmember on mine but the header would seal just fine. I ended up grinding the crossmember down where it touched and I also dented the header tube to give it plently of clearance to prevent rattles. So I would recommend denting the header tube for clearance.
If your engine or engine mounts have ever been taken out make sure your mounts are on the correct sides. There are part numbers stamped on the mount. They are at slightly different heights but will bolt up and cause you all sorts of problems if they are switched. I made this mistake once and it took me awhile to figure out why my headers didn't fit.