befuddled. my 63 230 has development a stalling/hesitation problem 1. I have to choke her on start up each morning 2. sitting in the driveway idling, she purrs, but, if i accelerate, she hesitates, almost stalls out before recovering 3. driving down the road, starting at about 45-50mph, she momentarily hesitates/stalls. not to the point of dying, but stalls... i changed out the fuel filter and installed a new Napa fuel pump last week. that hasn't helped.
Sound like you need a rebuild. If you ahve let the truck sit up for any duration the fuel will start leaving varnish and sludge in the fuel bowl. I took a carb off my stang and set it in the garage for 6 months. The fuel in the bowl had left a molasses mess.
Check your timing and readjust your carb. That is usually the problem with mine when it acts like that. Are you using points style distributor? When the module in my Mallory unilite would go bad it would also hesitate and just plain die sometimes and then would fire right back up again.
If it runs fine after it's fully warmed up, you might want to check the heat riser in the exhaust manifold. It's very common for them to stick open, which means there's no heat going to intake manifold/carb on cold starts. My experience has been an inoperate heat riser is more problematic on inline engines. If it is stuck, you may be able to free it up with penatrating oil or WD40, and work the valve open and closed until it moves freely.
i converted to HEI. yeah, i did a carb rebuild about 4 years ago, and yeah, it sat up while the body work was being done... heat riser is new...checked that manual choke that is working fine
