Well i am a new member so first let me say hey to everyone!

Then on the truck, i own a 1974 k5 Blazer...has a 350 bored over to a 383

Brand new Quadrajet 4 barrel carb on it...750 Cfm electric choke

Has from what i can tell(reccently bought this vehicle so im not sure) what looks like a Cadillac radiator in it, a lil smaller than what came stock in this vehicle im pretty sure and the previous owner seems to have compensated for this using 2 electric cooling fans...however the original crank fan isnt on the vehicle either.

Ive been tinkering ever since i bought it, it had a new ignition on it MSD, good from what i can tell...i checked and replaced the plugs and plug wires...checked and replaced the starter and starter solenoid.

Then i slapped a new battery in it, also ran new battery cables...and now to the problem....

It never ran what i would call "solid" first 30 mins of running it ran good...but after that you had to baby it a bit...thought it might just need a carb adjustment but i have adjusted and adjusted and it still doesnt seem to wanna stay running after it has been for 30 mins or so...i dont know what else to try and would really appriciate any advice at all, thanks everyone!

Welcome!

Start with the basics... air, fuel, fire.

Air filter clear? Fuel - do a pump volume test - disconnect the line, crank 15 or 30 seconds, and see how much you've got. Fire - how are the plugs, wires and timing?

Does a COLD motor start up pretty quick?