Jandro that combination should continue to make hp above 4600rpm(@ least to 56-5800).What carb are you using?Should be @ least 830 cfm with 1" spacer(hood clearance allowing).What ignition system?Make sure you're @ least 30-34 total timing between 2800-3000 rpm's.I personally prefer holley carbs(something I'm more familiar with) and MSD'S ignitions with pro-billet distributor (I don't concern myself with vaccum advance for gas mileage).Seek out and join a local Pontiac club in your area.I have chatted with a Tim Simpson(goatseeker) who resides in Ga.,maybe he can steer you in the right direction for membership.DO NOT depend on anyone not familiar with Pontiac engines wrenching (my)oops! your new engine

I'm trying to build my 69 WS Judge 400 to make equilvalent power using the RA exhaust without "stroking" the engine