Hi guys.
As my car was, I had the jetting what I felt was optimal for my setup for many years now. THEN I go and look for that extra tenth or so in the 1/4mile.
I install a Proform Main body on my 4780-1 holley. Follow the jetting recommendation except because I have both powervalves I opt to go with 72/80 jets instead of the 84's they suggest. At this point I swear the car makes more power than with the stock main body but nowhere to confirm this.
Plugs looked really white now compared to before so I figure I'll up the jets a bit. I put a PV plug in the rear and up the rear jet to the 84's. Car feels weaker now. But who really knows?
So I go racing Saturday, 1/8 mile. And I've slowed down by 2/10's. Not impressed. So up I go in jet because plugs still look lean. 74/84 now. Car picks up about a 1/10 and I'm back in the ballpark. Now it rains. Track closed.
So in the downtime I go up to 76/84 and first run Sunday it picks up another .05 and I'm basically back in the neighbourhood of what it ran last month and for the last couple years.
Now I up the rears to make it 76/87. Car ran .002 faster than the last run but picked up another mph.
I usually can say the car will run a 7.40 +\- .01 @ 94.5 mph. I was now pulling 7.424 and 7.422 @ 95.6 and 96.33 mph. Never had mph like that before.

So now I wonder? Is this Hp main body gonna pick me up in the 1/4 even though I seem to have slightly slowed my ET in the 1/8? And does it sound like I'm on the right track here??