Holley/Demon Carb stumble

Another story......
20 some-odd years ago my Dad was bracket racing his 79 ‘Doba which had a 13:1 360 in it.
He’d been running the same Holley 650DP on it for years.

At about that same time I had taken a 650 main body, knocked the boosters out, machined the venturi to a larger diameter, then did some porting and blending on it, installed downleg boosters, modified the metering blocks, and started playing with it on the dyno.
On the flow bench it flowed about 825cfm(calculated wet).
I got it working pretty well, and ended up selling it to a guy with a Dirt modified after it crushed the carb he had been using on the dyno.

So, my dad wants to go quicker, but isn’t up for buying a bigger carb. He knew about my 650 experiment and was curious if it would work for him.
He also likes doing his own stuff.
So, the decision is made to lightly port the 650 without replacing the boosters.
I do one hole, he “copies” it to the other 3.

We dyno it....... the signal at the booster is now a lot weaker, so it requires a bunch of jet be added.
This makes the part throttle rather rich, but the throttle response is killer.

We bring the car to the track...... the initial hit is fantastic, then some hesitation, then it goes.
The pump shot lasts way to long.

I install the shortest pump cams, rotated way around on the shaft so about 1/2 the lift is already used up with the throttle closed, put some 25 squirters in it...... its perfect.
Totally bog free.
It needed almost no shot because the main circuits came in almost instantly.

One little tidbit....... my Dad had messed with squirters and cams for several track outings and couldn’t get it to work all that well.
Like I said, he liked doing his own stuff...... but after a bunch of trial and error, he was thinking he was probably going to need a different carb.
He’d make a pass, try changing something, male another pass, etc.
A few times he asked for some guidance, but it seemed like he was determined to figure it out.
Finally, he decided maybe I should look at it.
So, based on his feedback I’m making adjustments to no avail.
I finally make a pass in it myself....... and can tell right away what’s happening.
That’s when I set it up like I mentioned above...... which worked fine.

Like I said earlier in this thread....... for me, a lot of the tuning is tactile........ especially the starting line stuff.
I need to “feel” what it’s doing.

As for my modded 650 experiment, it’s much easier to get the same kind of results from your 650 these days.
Just buy a $150 carb body and a primary metering block.