2.76 open to 3.55 Sure Grip...expectations too high?

Loosen the distributor slightly and move it around until you find the highest idle, then retard it as far as possible while still maintaining the high idle. If it doesn't run great, then change your vacuum advance line to an off idle port and reset the timing the same way. If the vacuum line was already at an off idle vacuum port, then move it to full vacuum, reset the timing like I described, and test drive again. Use which ever vacuum port works best.