[dub]

Hey guys,
I have a 72 Chevelle with a 383 Stroker. I just put on a new Holly Double Pumper, 650 CFM with a Air gap dual plane edelbrock intake manifold.
Runs great, but when I punch the throttle, it sputters and then kicks in, if Im at a stop, I punch the gas and sputters and nearly dies. But then catches and takes off. Any Ideas? Did I not tune it properly?
Timing is set at 12 degrees advance.

Next issue is that the motor under heats. Before the swap, it ran at around 190 degrees. Now it runs at 100-120. If I stop, it heats up to around 190, but then when I get going again, the temp rapidly drops back to 100-120...

Bad thermostat?

Any suggestions/troubleshooting is helpful.

Thanks,
Mike