340 misifre

I have a 727. I havent checked for ground or my secondary, I just assumed since it was running it was fine, but I wil check(i have a multimeter).

I dont know what r.p.m it cuts out except when I go to floor it, no matter what r.p.m. I am at. It seems to cut out at like 900 to 2000 and 4000 to 5000.
*complete stop to acceleration backfires/connects and goes/back fires alittle through exhaust twice while going/connects and goes and then stumbles and fights to get past 80* its like it just maxxed r.p.ms and the tranny is saying NO.
Connects=all 8 cylinders igniting.
I think I need to play with timing.

I had a vaccuum gauge hooked up, the vaccum is around 12, it fluctuates a little but it is with the stroke of the cam because the idle is sort of choppy and the needle kind of goes with the sound. However when I raise the r.p.m. up to about 1100 or so the idle really smooths out and the needles acts like it supposed to and steady's. I know on a properly running engine the needle is supossed to be steady but my cam isn't stock so I am thinking it is just the cam making it wiggle.

2 weeks or so I pulled the valve covers and all the rocker arms were moving and I had oil shooting all over, I observed the valve train and dont believe to have a sticking valve, plus the heads and valve train are all brand new and recently installed.

I may have burnt valves, I am thining about buying a valve retainer tool and checking my valaves out and cleaning them.

So far my plan is to check my secondary ignition and grounds, research some timing and play with my air fuel mixture. Also scope out a valve tool.

Thanks.