[DAVID GAGNARD]

I agree with all of the above...........My race motor is down now to be freshened up and when I dyno it, I still treat it like a new motor....I go thru the break-in process, even though I'm running a roller cam, after a 20 minute run, we shut it down for about 20 minutes or so and pull the plugs and check them, reset the idle and carb and basically check for anything loose (valve covers/water pump bolts,etc.)....

Then the fun starts, we start the pulls to max out at 5000 rpms and each pull there after increase it by 500 rpms till I hit the max (7000rpms for my motor).... Since it's not the first time, I do have a baseline for jetting and timing, afterwards we adjust the timing by 2 degrees each way to see how it acts.....

Nows the time to try anything you have in mind, I've tried different carbs and different carb spacers, found what works best with my combo........

I also agree, dyno the motor with the your headers and at the very end, I add my air filter for a pull or two.....

BTW: with my 14" diameter, 3" tall paper filter, I only lost 3 hp and the same in torque!!!!!!!!!!!

David