305 hesitation at higher throttle

[recian]

I've noticed this recently on my truck. It's way better now that I fixed vacuum leaks but 50% or more throttle my truck hesitates unless it's full throttle. It only seems to do this when driving. sitting still and revving the engine it works great so the sticky about hesitation won't do me any good. It seems to be worse when cold. Since there's no smoke or smell I'm thinking a converter issue. The exhaust is 100% original. I'm looking to see if anyone has any other ideas before I try getting another converter put in. I've thought about a magnaflow high flow since I can't remove a converter here and not put one back since it's a weld in not a bolt in so no test pipes for me.

 

[chubble]

Are you in New Bern, NC? If so I'm right up the road in Greenville.

What kinda carb are you running? Air filter/air intake? My truck used to hesitate alot because my carb is too big for the wee-oh-five (as HR would call it). So matting the gas dumped a **** load of fuel into the carb which just about flooded it (not enough air either) and caused and big hesitation. I replaced my air filter for one of the big 14x3 Edelbrock round filters and used a pair of stock air tubes from either side of the radiator just to help port cool clean air to the air filter. Has helped out tons in my throttle response and hesitation problems she used to have with the stock air intake with the vacuum port on it.

 

[recian]

My truck is still all stock. New air filter. I'm running the 2 bbl rochester 210. I've considered finding a quadrajet. My brother had one on his scottsdale 305 and it livened it up good. I'm unsure about the fuel filter. That's my only conscern. It was running good today. It seems to come and go. I notice it more when I attempt to speed up before the trans downshifts like coming out of a corner or attempting to pass. I should pull a plug and see what they're doing before going too far. Talking to the previous owner I know they've got at least 60k on them but having just bought the truck Idk what brand they are.
If I was to go with the 4bbl setup would it be wise to pick up the HEI distributor upgrade? More fuel needs more spark. I've heard that simple distributor change helps alot

 

[chengny]

I'm unsure about the fuel filter. That's my only conscern

If you haven't changed it - it should be a concern. You describe the classic symptoms of a clogged fuel filter.

See item 68 below:

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[recian]

I know it's got at least 60k on it so I think I'll pick one up this afternoon and see what happens. May smooth out my idle a bit too