Alright my SBC is annoying me now, I let it sit for 1 week, didn't touch it. It used to start on a dime, Now its really hard to start and misfires and rumbles under 2000-2500 rpm. If i rev it up, it seems pretty clean. I did have a couple scorched boots but i replaced those. Cap and rotor is good, plugs have been swapped out, no vac leaks that i can see, valves are adjusted well, i have compression air fuel and spark... Any Ideas?

I did recently adjust the valves but this issue was consistent before that...

 

I did find a little debris in the regulator when i disassembled it, Maybe i have some crap in my tank, going to take the carb apart later and inspect.

 

Carbed?

EFI?

Stock?

 

Carbed, summit racing 750 vac secondary carb. Vac advanced MSD streetfire distributor. built 357 forged pistons, alum heads, etc.

 

Update:

I have tried:
New coil
New Rotor
known good dist
New ignition module
New plugs
New wires
Known good carb
There aren't vac leaks as far as i can tell ( need to confirm with vac gauge yet )
Cleaned out fuel filter

I have a suspicion my fuel pump may be on its way out, need to confirm

 

what cam is in the engine? What is the timing?

 

initial timing is about 24-25 degrees

I have a .488/.510 234/244 duration

Camshaft: Performer RPM

Part #: #7102

It literally ran so perfect before i parked it, came back out to this issue, I dont get it.

 

Whoa, how much initial timing?

 

Well its far past my tab. That's with vac advance hooked up I should say. Not initial