86' seirra tranny problems?

I have an 1986 gmc high seirra and i just rebuilt a 350 small block engine. so i dropped it in ran great but it wont shift right. it shifted fine with an high rise intake i had on it but i found a better standard elderbrock intak and so i put that on there. since then it hasnt shifted right.

if anyone could help thanks. -thor-

If you have a turbo 350, the vacuum modulator needs to be hooked up to intake manifold vacuum. See what the vacuum reading is at idle.

//2000CAYukon