I don't htink the governor will have a big impact on normal driving upshifts....adjusting the modulator or modifying internal pressure with a shift kit will work better. The governor has more of an impact on WOT shift points and down shift for passing gear.
Tim, I would try using an adjustable modualtor(aftermarket) and not mess with the factory unit. The more you restrict the vacuum....the firmer the shift and it will hold a little longer.
CW tranny and 4.10 gears are a trip...we have that setup in our 70 L78 car and it really works
...and, with the stock modulator.
