Hi Russ I have a chevette kit also the over heating a quick fix the fan is to far from the radiator i used a plastic bucket cut to make a fan shroud that ended the over heating now it never hits over 200 degrees even on a hot Tennessee summer day ,,as for the seat you have , cut the back of the seat bottom ,the fiber glass box ,to 3.5 inches off the floor at the back and leave the front at stock height the angle will make the ride more like a GM bucket seat angle, lowering the seat height in the rear also improves your head height with the top up you mite not need a jell insert .see you only thought you were an iron butt , Do you still ride? my Dyna has it’s place in the garage next to the TD .