Well the added power in the hills was impressive. It was 50-70 F up there so the cht stayed about 206-210. TFT never went over 160 F. The little extra pep really helps getting into traffic easier. The roads going to Mt Rushmore were fun but I totally respected the posted speed limit, being the "law" is all over up there!
Logged approx 800 miles round trip on the 87 custom perf tune.
Some down falls were:
Mpg's at 80 mph 13.34-13.95
Thought the custom would do better than stock 14.5-15.75 mpg.
Every once in about 2 miles started to feel a pull in the motor. No it wasn't the compressor kicking in and out. Had it turned off.
A new problem arose. When hitting set on cc, started to get shudder in tranny.
I did raise the tq tip in +5 mph and this did not help the coast shudder. Also the 40-50 mph hiccup did not go away it's still there.
At some points during the trip it felt that the truck's nose was being pushed down and was being pulled from behind at the same time.
Lars