351 Cleveland boss

[gfi]

Hi Folks:

I really have a dilemma and here's hoping someone can help. Just got a fresh 351 C Boss 850 Holley about 511 hp. Runs horrid: Only about 4.5 inches of vaccum at idle, have to feather to prevent from backfiring and get the idle up then it seems to get going ok. #2 problem is that I cannot seem to get the temp to stabilize. It just keeps climbing.

Any help or suggestions would be great.

Thanks

gary

[Woodz428]

Vacuum problem sounds like timing,either ignition or cam. Or a too radical cam. But with the overheating as well, I'd be leaning toward timing. If the overheating was occuring separately, I'd say pop off the thermostat housing and look under the thermostat to make sure someone hasn't remove the round diverter that should be there. You didn't mention any plug readings or any other data that would help in tracking the problem down, idle screw settings, throttle plate position,jetting etc.