I'd spray 100 instead of 75, but here's what you do...
1. Retard timing two degrees per 100 shot.
2. Install a WOT switch and a button, don't spray until 3000 rpm. (window switch is easier though)
3. Colder plugs gapped a .035 is fine, never use platinum. Only copper.
4. 91 Octane.
5. Make sure your jetting is correct.
I've sprayed 175 on 5.0 motors with no fancy dyno tune or computer modifications. They were wet kits though. I'm not a fan of dry kits.
Most kits have their jetting spec'd out pretty rich from the manufacturer to keep kids from blowing their shit up. I confirmed this suspicion when I sprayed a 250 shot plate kit on one of my motors (wet kit) and the A/F ratio was <10:1 with the factory jetting.
Paul.