I've been tuning on my carburetor for a few months now and just can't seem to get it much closer. Air fuel at cruising is in the 14s and wot is 11.5-12.5 (running nitrous). It runs like a champ the only thing I haven't messed with is initial squirters.

Holley 750
Blue pump cam in primary, #2 position for secondary pink cam.
Front initials are 28 rear is 32.
71 primary jets
84 rear jets(no rear PV)
Not sure how to check size of primary PV

Plugs are slightly black on the ring but has a nice brown color to it elsewhere.
(ngk#7 plugs)

Before I started tuning it had a nasty stumble but I got rid of that pretty much.

 

theres an obvious fuel problem, after using the dyno at ranken tech my max hp was 260 at 5600 rpms. rediculous. my rpm band should go to 6000 atleast and have almost 100 more numbers. if your fuel pump isnt stout enough, will it drop hp? (mechanical 110 free flow pump) didnt get a chance to check fuel pressure to see if it dropped

 

The accelerator pump is only a factor while the throttle is being opened.

The number stamped on the edge of the power valve flats only determines the manifold vacuum under which it will open. If it says "5.5", it will open when manifold vacuum drops below 5.5 in-Hg. Stock is 6.5.

The amount of fuel let in by the power valve is a function of the power valve restrictors. In a standard Holley, they are pre-drilled and not adjustable/replaceable. With billet metering blocks, you can put in different restrictors.

The float levels and ignition timing are pretty important. Have you checked them?

What are you using for an air cleaner?

The standard "old school" method of determining mixture ratio is to read the spark plugs. To do that, you need to start with clean plugs and shut the engine off immediately after making a pull. Much easier to use a wideband O2 sensor system (although it does cost a little bit of coin to get and install). Probably the most efficient method (time-wise) is to have the car on a chassis dyno with O2 reading equipment, being operated by someone who knows how to read the data and adjust the tuning.

 

I have a weiend triangular style air cleaner and float is good, I have Wideband and reads about 11.5 wot, do you think 84 jets are too big for secondaries for a 750 DP? It has a noticeable bog when I'm at the top of 3rd gear. I'm thinking my 84 jets are drowning it out

 

I would drop down to 80's in the rear and see how it pulls. If it's better then fine tune them from there.

 

That's what I'm thinking, and I'm running a timing controller box and is set at 36 degrees without the nitrous