Doc here,
imp:
Check to be sure 5 and 7 plug wires aren't reversed..HAND OVER HAND them to be sure..they are the only two wires next to each other at BOTH ends,,and will cause the exact problem you have..
A lot of guys Pro and Novice both, will blow it off and say" Yea, Yea it good I sure" and find a month later and a ton of UN~needed parts later that 5 and 7 were reversed..
Check your static timing also..
Number 1 cylinder TDC compression, Timing marks aligned, Both intake & Exhaust valves closed , no pressure on the lifters (not too much slack either..)
*--->If you can't co~ordinate these, you have timing chain/gear issues..<---*
Drop the dizzy in, and watch the rotor, It will advance clockwise a bit, this is because the gear teeth are diagonal cut, It will go about a tower in a half in some cases..Note the amount of change and then withdraw the dizzy.
Line the oil pump shaft up to that location with a large screw driver, and reset the dizzy, for number one plug tower, allowing for advancing as the gears seat..
The easy way to do this is make magic marker lines on the base of the dizzy, for exact #1 plug tower, and the difference of rotor movement as it seats..due to the cut of the gears..(I.E...#1 and the amount of distance BACK required to make it sit on #1 plug tower when bottomed out..)
#1 plug tower in the stock location for SBC's is 5 to 7 O'clock, (depends on year, and obstructions) 7 is usually good.
Direction of rotation is clockwise.
The F.O. is 1 8 4 3 6 5 7 2..
This will clear or include the cam Timing and dizzy timing as suspect..If it all checks good move on to the valve train..
Doc
imp: