I run an IT7 car, and I am planning to run a test and tune on Friday (9/9), but I am concerned about my carb.

The carb has been installed on multiple motors/intake mani's and it never idles well. typically I can't get it to idle at all below 2000 rpm. I have run the car once with this carb/motor combo, and it ran great until I had to pull off due to losing coolant through a loose hose connection. The motor saw about 240 degrees and seems to be OK. Before I lost the coolant I was seeing about 180 deg water and 230 oil.

The other night, I noticed that the header pipes were glowing a dull red - in a shop with so-so lighting. This was while the car was idling at about 2k rpm.

I'm concerned that the car may be running lean because of a vacuum leak, and I may be risking my motor if I run it this way. But I don't know that it's not normal to have a dull red glow at the headers. It also, doesn't seem too unreasonable to think that a vacuum leak that messes up the idle circuit won't matter much at high rpm's when the primary and secondary circuits are in play. Unfortunately, I don't have EGT or A/F gauges or a known good carb.

Can anyone offer any help on this?

Thanks,
Neil