340 misifre

Hello,

I recently built a 340 with a hughes engines whiplash cam and put it in my Dart. I am having a misifre at high r.p.m.'s or under load. 0 - 65 is smooth and effortless but once I floor it from 0 or at 65 m.p.h. I have a misfire and cant get the car to go over 80m.p.h.

I have good compression, spark in all cylinders, voltage regulator is fine, no wires are touching, standard mopar performance orange ecu box, distributor. eddy 660 carb. Vaccum advance, idle time is around 20-21 and all in is 32 or 33. I cant seem to find out what it is I have great spark in all cylinders. I have basic wires from an auto parts store, and 3.23 gears. I think I should be able to do over 80 m.p.h in this car as I took it to the track and it ran 18's at 80 m.p.h. I believe it can do better.

When I do a burnout it misfires like 2 or three times and then stops missing and then it really takes off like it should. Sometimes a backfire can be heard in the headers. I have richened the fuel mixture, leaned it out, adjusted timing to 35, checked all my wires, changed my plugs and still cant figure it out. Perhpas it is my coil but the resistance seems fine(around 1 ohm)

I want to floor the car and twist the distributer untill it stops missing but I dont think that is a good idea.

I think it is timing.
Can anybody help? I would really appreciate it.