2 Speed power-glide odd shifting.

[Gmtruckguy92]

Hey guys, have a 67 c10 with a freshly rebuilt 327 and it also has the 2 speed power glide tranny, the trans wasn't messed with when the motor was rebuilt.

I started noticing that while driving right before it shifts it acts as if its in neutral and the rpms go up then it seems to catch the gear and shift. Wasn't positive if it was due to the kick-down not being attached on the carb and perhaps its stuck or what the problem could be?

any advice would help!