MAC Complete Exhaust Install... Problem Fixed

Just installed a complete MAC exhaust system on my 1993 GT Mustang with 89K miles. The components were MAC Equal Length Headers, Mac X Pipe and Mac Cat Back Exhaust. I purchased all the components from my local speed shop and installed them yesterday. I stayed with MAC for all components to ease in installation of everything. The install took longer than I thought it would as I ran into a lot of problems getting the headers to fit. The drivers side just would not bolt up no matter what I did. The passenger side fit like glove and installed in no time at all.

I could not figure out why so I started searching the mustang forums and came across a fix for this problem and thought I would pass it on to all here.

The problem is with the motor mount of the car. The mounts were original and in need of replaceing. So I replaced them first with factory replacements from Autozone. I installed them and the headers still would not fit. So I searched the forum again and found that I needed to install convertible mustang mounts. I took the factory mounts back to Autozone, purchased the convertible mounts and installed them on the block. "Low and Behold" the headers now fit like a glove and gave no issues after that. Everthing else also bolted right up with no problems. The car sounds great and has more of a seat in the pants feel now. Next on the list of things to be installed is a set of 3:55 gears. I think I will pay someone to install these though...

Just want to sya thanks to all on the board. I could not of done this without you. I would of never thought something like the Motor Mounts could cause such issues with exhaust components.

I helped a friend put shorties in an '86 GT he had... when we first installed them we realized the passenger side header was resting on the k-member when it was bolted in place... we eventually traced the problem to a torn motor mount on that side. he bought convertible mounts, we remounted the engine, and the headers fit. unfortunately, we discovered that they were 351W swap headers meant to bolt one to stock-style midpies, so we couldn't use them afterall and ended up using the stock headers. oh well.

personally, i'm goign to spend $120 and get polyurethane motor mounts to match my tranny mount.