Exhaust leak and carb vacuum - sync problem?

Hi everyone,

I'm trying to sync up my carbs with some dial gauges. I have a small exhaust leak at the connection between my header pipe and muffler pipe. The connecting gasket is missing. This leak is on the #3 cylinder.

I'm wondering if this leak will affect the vacuum that the #3 carb pulls due to decreased back pressure.

Thanks,

Andy