Question on holley 4150

I'd buy a wideband 02 sensor.

Innovate sells a very user friendly kit, and FAST sells ones that are a little more money, but easier to use and read while driving (obviously, you need to be careful doing that).

It really helps you diagnose where your problems are.

Rich at idle? Lean/rich with the squirter?

I've always found that if you get your four corner idle squared away really well, the rest gets easier.

Steve