Ramblings: AMC Trendsetter side exhaust - love it AND hate it!

From 1968 - 1974, AMC offered Trendsetter side pipes as a dealer installed option (also known as Side Winders).  The factory high flow manifolds are 2 1/4" ID while Trendsetter side pipes used 2 1/8" I.D tubing and mufflers with a 2" flow path.  There are several benefits to the Trendsetter side pipe system:

1. Less heat in the interior

2. Louder

3. Lighter

4. Aggressive styling

I had the system re-made using 2.5" galvanized tubing, 2.5" Classic Chambered galvanized mufflers (2.5" flow path with unique chambers to scavenge exhaust and NO glass packing to wear out) and 2.5" polished stainless tips.  I picked up 21 rear wheel horsepower over the original Trendsetter system with no other changes! 

After putting about 40,000 miles on this system, I have the following recommendations for anyone wanting to install Trendsetters on their AMC:

1. Use (2) lock nuts with blue LocTite on the head pipe flange bolts.  This will keep the head pipe from loosening up.  Keep a spare set with you in your car.

2. Keep spare 2 1/8" Fel-Pro doughnut gaskets (available from O'Reilly Auto Parts). The Trendsetter system uses the body (instead of the frame) for mounting.  This means there is a lot more flex than a traditional frame mounted exhaust.  As such, you'll be more likely to blow up your head pipe doughnut gaskets.  I've gone through a set about every 8K.  MOST exhaust shops don't stock this part and when you blow out a gasket, the vacuum leak really affects drivability (stalling, coughing and sputtering).  So, keep at least a set with you in your car.

3. Install polyurethane motor mounts.  I installed new rubber motor mounts 4 years ago.  They became soaked with oil due to a leaking front and rear main seal leaks.  Engine oil breaks down the rubber engine mounts (over time) and causes excessive flex and eventual failure.  Polyurethane motor mounts are impervious to engine oil, dirt, grime, etc. and won't break down.  They will transmit some extra road noise (especially if your engine, harmonic balancer or torque converter <if equipped> are out of of balance).

4.  Coat your exhaust system with 2000 degree satin black ceramic coating from Techline.  I had this on my original Trendsetter system (Quality Powder Coating in Carrollton, TX is a dealer for Techline).  I coated just the outside and it completely prevented burns on legs when entering the car.  Additionally, I was able to touch it while running without scorching my hand!  I will be having this done as soon as I can on my new system.