Solid motor mounts are an excellent modification for a 3000GT or Stealth. It was among my first upgrades and I recommend the same to all 3/S owners. The stock Mitsubishi mounts wear and weaken. The rubber cracks and the engine moves excessively, causing rough driving and poor throttle response. Two kinds of solid mounts are available:

• Polyurethane, which use the stock motor mount frames but replace the rubber with hard polyurethane inserts
  
• Solid, which are entirely new pieces with no flexible material. You can get these at Maximal Performance.

Installing polyurethane or solid mounts with the engine in the car looks like a daunting job, but it is easier than it seems. What follows is not a comprehensive walkthrough, just my tips and recommendations.

Rear mount: Some have said that they got theirs out without jacking the engine, but I prefer to raise it slightly. With the front motor mount also disconnected, the engine will come up about 1.5in (it moves plenty when attached by just the weak side motor mounts). I strongly recommend using a hoist and not trying to lift the engine using a jack on the oil pan.

Once you have removed the cross-pin and the 4 bolts securing the mount to the crossmember, simply turn the base of the mount up 90 degrees, so that it faces the firewall, and then a 90 degree turn to the driver’s side, swinging the bottom of the mount out underneath the bracket. Now that I’m used to the motion I can put it in and take it out almost without looking.

Front mount: Positioning the front mount is very easy, but actually getting the cross-pin and the 3 bolts in the base to line up can be difficult. You’ll want to get all the fasteners started, including the cross-pin nut, on the rear mount first because it is already tough to access.

The easiest way to ensure that the bolts on the front mount will line up is to attach the mount to the engine bracket with the cross-pin first. Then, position yourself such that you are looking straight down on the front mount. Rotate it down until the holes in the base line up with the threaded holes in the front crossmember, even if this means that the base of the mount is not flush to the crossmember. Install the bolts and tighten them slowly. This will force the front mount to lower itself onto the crossmember.

Driver’s Side: The driver’s side mount offers few challenges. Do not be afraid to pry slightly as you work the cross-pin through the mount.

Passenger’s Side: This mount presents difficulties similar to the front mount: I installed this one last, and the engine will not move much with the other three mounts installed. It is easiest to bolt the mount to the firewall and then work the pin through. Usually I have to pry the mount up a touch and give the pin some gentle taps with a hammer. Keep in mind that you’re working with some very stout parts here. You don’t need to be gentle.

One more tip: When bolting this mount to the fenderwell, be cautious when sticking the bolts through and getting them started. If you drop a bolt, it will fall into a cavity and be inaccessible. I like to put the bolt on the end of a socket and long extension, and then slowly bring the bolt through at a slight upward angle.

As you can see, the problems were few. If you’re swapping mounts with the engine in the car, a bit of prying is all you’ll need to worry about. The rear mount is nowhere near the ordeal that it appears to be. Now that I’ve done it once, I’d take that job over many others.