Possible timing issie

Man, I hate to bug you all again but it looks like I need some more advice.

It's not the electric, haha. Ever since we changed the wiring I start on time every time.

This came on suddenly: I went to start the van, it started right up and ignited, but then sputtered and shook to a stop. I repeated about 4-5 times then managed to limp the mile home by keeping the choke on-otherwise it would just die outright.

I've seen people rotate the distributor cap-to adjust the timing, I think.  Any advice on how to proceed is appreciated, as always!

I also have a good mechanic handy too.

Im betting its not timing!!!!!!!!!!!!! if u r closing the choke to make it stay running ?? its a fuel delievery problem!!!!!!!!!!!! You are NOT getting enough gas thru carb-maybe fuel pump?? maybe fuel stoppage in tank , filter or carb?? pull the dip stick & smell the oil on it??- smell like gas?? =fuel pump!!

Sounds like weak fuel pump or packed in filter. Look for small rust particles in the filter. Choke won't fix bad ignition.

Ooops-I meant "issue" naturally.

Sounds right-there's a loud hissing sound coming from the carb. It runs smoothly now, but dies after about 40-60 seconds-just shuts off.

If it was me I would start with disconnecting the fuel line going to your fuel pump from the tank. Take a gas can and run a new line from the can to your fuel pump and see if that makes any difference. If it runs well then your problem is plugged line or fuel filter or crap in the tank which would have to be dropped and cleaned and filter replaced. If it still runs and dies then maybe the fuel pump or a blockage at the carb inlet not allowing fuel in. At least then you will no where to start cleaning if it's a clog issue. Unfortunately I don't know what shape your entire fuel system is in to give a better answer. Is everything old and original, or have you done any upgrades to it?

start with the fuel filter if it has one...
may have one where the line goes into the carb..
then fuel pump.. can get from autozone for like $22

I found out whereabout the hissing sound is coming from-steam is escaping from somewhere below the engine block, towards the back, on the driver's side. Not blasting out at high velocity, but definitely there. There's some corrosion in that area as well.

My engine has been rebuilt, and the fuel line and filter are about 3 years old.