Adjusting my carb to my new heads

Hi,

Recently I swapped the heads of my 318. The old ones were stock 318 small chamber heads with some cleaning and light porting. The new ones are also 318 small chambers but fully ported with 1.94 and 1.60 valves.

The specs on my car are:

-Mopar solid .528 cam
-Flat top pistons (about 9.8/1 with milled heads)
-Eddy RPM intake
-Headers
-Holley 650 double pumper
-3.91 rear end
-MSD distributor with 2 silver light springs (18 initial / 36 total or so..)


Well, with the old heads I was running 69 jets on the primaries and 75 on the secondaries, with 32 nozzles and 6.5 power valve. When I changed the heads I felt the carb was pretty lean.

I tried some different jets and nozzles. By my vacuum readings I chose the 4.5 power valve.

Right now I'm running 73 jets on the primaries and 79 on the secondaries. The nozzles are 35 on the primaries and 37 on the secondaries.

What I feel is some stumble when I try to maintain light throttle, at about 3000 rpm. I was feeling some big stumble when I stepped on the gas to WOT, but I increased the nozzles and it got better, but it still stumbles lightly.

I am a bit confuse because sometimes I really don't know if it's lean or fat. I was thinking the primary was lean but when I incresed the jets it got worse.

One detail is the gas has 25% of ethanol here in Brazil.


Marcelo