Timing, Vaccum leak or Carb issue?
 

Hello fairly new to owning a older Ford had one for a dd few years ago 1978 f150 4x4 I6 4 speed. Anywho I recently picked a truck to plow my driveway with (i live lower peninsula of Northern MI) its a 1973 F250 4x4 dana 44 closed knuckle and came with a 360 4v with a c6 and divorced transfer case (old gentelman claimed it has been swapped to a 428 but i havnt measured stroke yet im willing to bet its still the 360 but doesnt matter he built with his son and sold becaue he has cancer and ive been after it for years lol...) and its been swapped to a 1979 f100 cab, bed and front clip. Got both titles so ran the numbers. I got it home and first off realized it had no spark replaced the coil with an Accell super stock and got great spark. Its still running points also it fired up but ran real poorly so rebuilt the carb as well...it has an Edelbrock 4 bbl on it with a 2 bbl 2100 motorcraft manual choke. Itll fire and if i can clear it out seems to hold high rpm alright (no popping) and have decent throttle responce. Almost runs like timings off but set tdc and pointed at 1 on the cap. Also it doesnt really help moving the distributor around while its running or the jets on the carb. I'm kinda outta ideas at the moment...maybe a new HEI distributor is next I dont much care for points and i dont want to dump money into distributor just because ebay has one wire Accell's plug wires and all for fe's for $130 shipped. I'd appreciate if someone could maybe just point me in a direction to look into next im used to wrenchin on Chebbies as im currently mostly a darkside man (pls dont hold against me lol) but have always loved the 73-79 dentsides some of the meanist trucks ever made imho. thanks in advance, Cody

Does it stall when returning to idle ?

Maybe an intake manifold leak? I know my I6 would run really really crummy at low rpm and would struggle to get up in RPM's, but would be OK once it did. Cracked intake manifold tab was allowing a big leak. Something to check.

I do belive the condensor was bad as well as some junk that was in the tank. Ive cleaned the tank out better now (took right out and cleaned). I pulled the trigger on the hei as im more familiar with and got a new set of wires and plugs too. Waitin on distributor now update after i get it stabbed in....i also am gonna change the canistor filter and carb filter again just to b sure because of the dirty tank. Thanks, Cody

I would still wonder about the tank. I just replaced the tank on my '74 F250 which had similar symptoms, runs much better now with only some minor carb tuning needed.

Prior to replacing the tank, I tried to clean out the old one first. Even after emptying the tank and flushing it a couple times, I kept getting varnish mixing with new gas. You could smell the bad gas in the exhaust as well (kind of a sweeter fuel smell, but definitely still a fuel smell). I had replaced the entire fuel system outside of the tank at that point (new carb, fuel pump, filters, fuel lines, etc.), so I tried to rule the tank out by running a fuel line into a gas can in the bed of the truck and running the truck off fresh gas. Ran great, so then bought a tank and gave up on cleaning the old ones out.

Thank currently i do have the gas line ran into the bed in a gas can. Once running a new tank will b on the to do list