Fuel or ignition or what? Need some help

[70stroker]

Alright guys i have a 460 bbc with a 177 weiand blower on it. I am having some issues with it dieing and needing some advice. I appreciate anyone who reads this long post and gives me a few ideas because i am at my wits ends.

About a year ago i droped a valve in my bbc and pulled it for a rebuild. Put a scat bottom end in along with alot of other goodies. When i was building this motor a buddy of mine had a nice new hei in his shop he said i could use, so i did. Anyhow i got it running back in june. Between june and july i put about 200 miles on it and never had any problems, It needed tuned a little but i was going to do that soon. Then he tells me he is ready for his distributor back so i order a summit hei. Anyhow i got busy for about a month and half and the truck just sat in my shop awaiting the hei. So last weekend i went out and put it in and timed the motor.The truck starts nice and easy with one pump of the gas. You can sit there and let it idle all day long, however when you go to drive it you get about a mile or so and it acts like it empty on gas and spits and sputters till it dies. You then start it back up and it wont hold a idle and just keeps dieing. You let it cool down about 30 min or so, then you can fire it back up idle it or drive it about a mile untill it does it again. IT was about 100 degrees the day i put the dizzy in so i thought maybe vapor lock, however last night it was about 70 here and i took it out and it did the same thing.

I dont know what to even look at, electrical? Fuel pump? which is mechanical. Perhaps a bad dizzy? even tho its new.

Any how i did rewire the whole truck with painless while i rebuilt the motor, so i could be electrical, however if it is why did i get 200 miles out of the motor running fine with the other dizzy?

Could it be the dizzy?

Could it be a fuel pump with a cracked diaphram leaking internally and starving for fuel?

Carb?

Any i deas on what to check? Thanks in advance