Had a similar problem to yours. The dist you bought was it an electric unit or points set up. Also have you checked the following items out.
Compression test (Blown head gskt) , Spark plug leads (Faulty), Crct spark plugs (essential), Distrbtr cap (cracks/ corrosion), Coil (dfctve), Carbie's (Float units). Suitable main needles, Fuel pump & filter. Just for starters.
Also do not alter oil pump at this stage, to check if the Distribtr is out 180* simply change the distrbtr leads so that the #1 Pstn on the distrbtr cap is occupied with the #6 lead & reset your other leads accordingly. 6 2 4 1 5 3 then test it by starting.Simplest way I know of how to check this out.
Good luck. Regards:Alan.