THM 400 2-3 hesitation; G-05 coolant and intake mfld gasket

Two questions today:
1. Tranny problem -
My 3 speed THM 400 (1985 Chevy pickup) hesitates during the 2 - 3 shift. It seems like it stays in both gears until I lift my foot a
little to "baby" it thru the shift. I have a tranny temp gage and the problem does not vary with tranny temp.
Tranny has 175K miles on it, majority of which is city driving. I just got through changing the filter, and that did not improve or worsen the problem. My tranny oil is 80% Mobil synthetic (Every 20K or so I drain 4 quarts and replace with synthetic.)
I would like to avoid a complete rebuild. Would a shift kit (like TransGo) help?
2. Intake manifold gasket problem -
'85 pickup again. I originally used green coolant, for 16 years. It tended to clog the radiator a lot, so I switched to DexCool (red) for a while. Heard horror stories about it so two years ago switched to G-05 coolant (yellow color). Starting a year ago I have slow seep from intake manifold gaskets, foward end, both sides of engine (big block with aluminum intake manifold). Need to replace the gaskets, but want to do the job only once and have heard that many people have repeated gasket failures when using DexCool in late 90's and up pickups. DexCool is very similar to the G-05. So, it boils down to question of whether G-05 is just as bad on gaskets as DexCool. Anyone know?
Henry
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Probably not. A transmission with 175k miles is worn out. Get looked at by a professional.

Its the Acidity of the coolant that does damage. Flush your system once a year to help.

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