Excellent combo. I ran a similar combo, but with an rpm Airgap, and a bit more cam/ compression.
With a 2600TC and 3.55s, that thing should be a tire-schredder.
If it is not, it's only because you have not yet figured out how to release the demon!, lol.
Your carb is not too small.
Your car is not that heavy. (mine is 3650 with me in it)
Your starter gear is not too tall. (3.55 x2.45= 8.70)
And your stall, (2600) while being a lil low, is not too low for 3.55s and 28s.
Your cylinder pressure is likely to be over 177 psi, (same as mine), so that will make up the difference.
So I'll tell you what I think is happening, cuz it happens to almost everybody.
I think your Transfer slots have or nearly have , dried up.
That Whiplash (I'm assuming a Flat-Tappet grind), is the 318 grind which is 213/226/109+5. At idle, it presents itself as about one or two sizes bigger as compared to a non-Whiplash type cam. Hughes does not publish their advertised specs, but a lot of their older cams were ground with ramps of about 46* so that would make it ~ 260/272 advertised. Cut on a 109, that offers ~48* of overlap, and in at 104* makes the Ica to be 54*. And the Wallace spits out 177psi at 500ft elevation. Badaboom!
Because you have so much pressure, you will have a ton of low-rpm torque. Buttum I'll take a guess and figure that you put a ton of idle timing into it to smooth it out. Like maybe 20* or more. This allowed you to close the throttles quite far to get the idle-speed down. Am I on the right track?
If you did that, then, you accidentally more or less shut the transfers off..... which creates the almost incurable tip-in stumble.
>The cure for this is real simple, just open up the throttles a couple of turns on the Idle Speed-screw, whatever it takes to get rid of it. Of course two things will happen when you do that; 1) the idle-speed will go up, and 2) the Idle fuel will go rich.
>To cure the fast-Idle, just retard the timing. To about 10/12 degrees with that cam, looking for an in-gear idle-speed of about 650/700.
>To cure the rich low-speed, just close the mixture screw back where they should be, around 2 turns from lightly seated.
> retarding the timing back to normal is gonna introduce two new problems, namely; insufficient Power-Timing AND probably a lazy midrange timing curve. You gotta fix these inside the Distributor.
Alloy heads and hi-compression, like about 32* PowerTiming, maybe 34* But not 36/38 like open-chamber iron heads. To get there from 10/12 Idle-Timing will require a 20* "governor" in the D. If yours is not 20*(marked R10) then you have to either get one, make one, or get/install the FBO limiter-plate.
After this is done, you will need to modify the timing curve by subbing in various advance-weight springs.
After this is done, you can begin tuning your Vcan, to make up the Part-Throttle timing you gave up when I told you to back up the Idle-Timing to 10/12.
As for tuning the carb;
The basics:
First; I'm assuming that I'm correct in that the transfers are slow or dry. If I'm wrong about that then from here on is just for your perusal.
>make sure your PCV is correct, plumbed with the right PCV hose, to the nipple on the FRONT of the carb that exits below the primary throttles. Plumb your V-can to ported spark, usually the passenger side nipple. If you have power-brakes, plumb the line to the plenum, or to the large nipple on the REAR of the carb if it has one. Do NOT plumb it to just one single intake runner. Make sure your cooling system temperature runs stable, and I recommend to run at least 180*. PROVE that there are no intake leaks, especially not into the CrankCase,and that ALL the air that is entering the engine, is doing so thru the proper carb circuits. If you have holes drilled in your primary throttle-blades from a previous install, this combo does not require them, so solder them closed.
Begin by; removing the carb, drain it, lock it on the curb idle screw, flip it upside down, and adjust the transfer slot exposure under the primary throttles to be dead square to a tiny bit taller than wide. After this, DO NOT change this setting unless I tell you to; this is extremely important. If you change it, and don't tell me, I will give you all the wrong answers.
Close the secondaries up tight but not sticking; then flip it back rightside up.
Reset the mixture screws to 2 turns from lightly seated. Be sure the float-level is set right, not lean. And finally, re adjust your accelerator pump to begin spraying a mist to fine droplets, just as soon as you very gently touch the throttle.
Now fit the base gasket and make sure it fits both the carb and the intake, then bolt it all back together. Fill the bowl(s) thru the bowlvent, then
> reset the ignition timing to 10/12; and roadtest it. Just the low rpm /low speed response mind you, and specifically the Tip-in at zero-mph.
Results;
If you still have a stumble/hesitation/bog/etc
you can increase the Idle fuel with the mixture screws to no more than 2.5 turns. If that seems to be working, but still not cured; you can give her more fuel from the Transfers, by increasing the idle speed-screw adjustment, 1/2 turn atta time, but when you do that; first put the mixture screws back to, in the range of 1.5 to 2.5 turns. Do not increase the idle speed-screw adjustment more than about 2 turns. If the stumble is not/has not, disappeared, something else that I haven't thought of yet, is wrong. Recheck your accelerator pump shot.
IMO, this is a well thought out combo, and just needs a lil tuning to make it great.
