How hard to install a Tremac 3550 into a 66?

The TKO has probably dropped in price due to the TKO 600 or whatever it is.

The install is as difficult as installing a transmission. The key is the fit. On my 65, the engine does tilt back slightly, but my driveline angles are good to go.

I don't know how much power they take, but I can powershift with my 331 (475 FWHP).

The kit is nothing more than what holds the trans in the car. It is made to tilt back in the early stangs just because of the physical dimensions (i.e. small)

I went through Fred at www.darkhorseperformance.com . Fred is a pretty cool dude, and he will answer your tech questions over the phone.

ONLY PROBLEM
One time, my first voyage to Salt Lake in the 65, I had a little tranny trouble. After a few hours of cruising, I decided to pull into Conoco and check out the crotch rockets. My car wouldn't go into gear after I parked. I waited a little and had to eventually shove it into gear. It did that on the way home soon after.

Now, once in a while, I grind it in reverse, but it is pretty rare. I am happy with my TKO. No matter what 5 speed you have, if it can handle your power level, you will like it. Overdrive rules.

what is causing the grinding?

Not exactly sure. I called Fred, and he suggested clutch adjustment.

Not all cars (65 - 66) does the 3550 fit that well. In my car, I had to cut the top of the transmission tunnel and raise the back of the transmission almost 2 inches to get the driveline angle correct. You can install it with the the engine at 6 degrees, if you do not mind you headers pointing at the ground, and draging over speed bumps. If you do not need the torque handling, but want a 5 speed, put a T5-z in. The T5-z will handle most 331-347's in these cars due to the car's weight. If I had the choice again, I would have gone with the T5-z.

John