i re-jetted the primary of my holley 570 and with that i get about that magic 14.7:1 on cruise. but it has a bit of lean bogs when i just slightly accelerate so i wanted to go one jet size up. don't have one, so it'll be two for the moment should I ever get around to do it.
13.5 is about perfect for WOT I found. you're a bit onm the rich side, but as Tad says, that seems to be what carbs want. Whereever you check on carbed WOT A/F ration everyone seems to agree on this one

 

Drove it for a good bit today and noticed something odd.

It was my understanding that at any give speed whatever engine rpm gives you the highest vac reading would also give you optimum fuel mileage.

According to the vac gauge as rpm increase so does vac. for example im pulling 15ingh at 2300 rpm I accelerate up and vac drops to 10 ingh...okay so far it makes sense. I stop accelerating at 3200 rpm and maintain 3200 rpm...vac now reads about 17 or more.....I doubt this would give better fuel mileage...

Whats going on here?

thanks

-Gun