Heartthrob exhaust not sealing to manifolds
 

I installed a manifold-back system from Heartthrob (the same kit available from JC WHitney or LMC). Had to put a dent in the passenger downpipe to get around the bellhousing. Then after I had all my pipes routed, clamped, and hung, I went to tighten my stud nuts/springs. After they bottomed out I got up and looked in the engine bay, and there were gaps where the donut seals the downpipe and the manifolds. I used the same length studs that I had on the truck initially, and the springs are even a little taller because they aren't compressed down from years of use. Has anyone else had this problem? Is it the donut seals Heartthrob sent me or is the angle wrong on my downpipes?

Re: Heartthrob exhaust not sealing to manifolds
 

Drivers side

Re: Heartthrob exhaust not sealing to manifolds
 

use shorter studs

Re: Heartthrob exhaust not sealing to manifolds
 

Thought about that but since I used the same length studs as what I removed and given what a royal pain it would be to pull the manifolds to swap out studs, I wanted to see if there was something else causing my problems. Seeing how heartthrobs kit is an OEM style replacement exhaust system and tons of people on here have used them with no real problems, I'd find it rather unusual that OEM studs would be too long.

Re: Heartthrob exhaust not sealing to manifolds
 

im with El Dorado Jim. if you ran out of threads on the studs then that is the problem. you could probably jerry rig it by using spacers or stacking washers or even get a cheap tap and die set and make more threads on the studs.

but ideally new studs are the answer

Re: Heartthrob exhaust not sealing to manifolds
 

Looks like mismatched parts to me. Are you sure that manifold uses a "donut" seal? Manifolds that use those usually don't have that material that looks to be about 3/4 to 1 inch thick below the flat surface where your studs screw in. Many later manifolds have a rounded flange such that the pipe seals directly to the manifold without using the seals. If that manifold was meant to use the seals, it would be beveled where the seal fits. The picture looks like the seal is against a flat surface with nowhere to "seat" to. Chip.

Re: Heartthrob exhaust not sealing to manifolds
 

oem should have the coil springs to lenghen the the area between the flange and the stud

Re: Heartthrob exhaust not sealing to manifolds
 

Some donuts are thicker than others. For example, the ones that came with my aftermarket Dorman manifolds are thicker and beefier than the ones included with my HeartThrob kit. I'd stop by a muffler shop to see if they have any that are thicker than yours.

Re: Heartthrob exhaust not sealing to manifolds