spark plugs

Great info. Appreciate it. I'm on a very tight budget, any suggestion on where to find a CHEAP fan shroud. On the running better with hotter plugs subject. could that 750 holley model 0-3310-2 4160 with 72 main jets stock secondary metering plate and 6.5 Hg power valve be too much gas? Once again 400 bored .040 over, mild cam, dual plane intake, stock manifolds. I was stumbling above 3500 rpm, hotter plugs seemed to help.