383 power?

Rumble, no, just stock port with 5 angle VJ, back cut on the intakes (stainless nailheads) and some milling. It replaced the "TRW/MP.509" setup that was trashed.

On the carbs, Holleys design tends to cover a lot of issues by dumping fuel at the problem. Where Cater decided to use other means to get the air to do the work it needed to do. Properly sized and tuned carburetors will make nearly identical power. However, having a bad one does happen. Something like pasages not drilled, or a loose booster. I've never had a bad one from either. Demon/BG is a whole 'nother deal and I have yet to get one that doesnt need to be taken apart due to production issues prior to mounting... but those two have always been good straight away.

You can get that power level pretty easy, but the work has to be good, and the parts have to work together. It's that simple really.