HEI conversion problems

[jpsage]

Hi,
Awhile back I installed an stock gm hei in my 72 c20. I bought a rebuilt gm hei distributer and associated parts from my local NAPA and went for it. After about 2500 miles, it wouldn't start because of no spark. I took the cap off and fiddled with the rotor, put it back together and it started right up. Then I blew a timing chain and ended up putting a new crate engine in. Now the hei is still acting up. The truck won't start and I will tear the cap off, fiddle and put it back together and it will run again. I have replaced the coil, cap and rotor and it still happens. I thought maybe the current demands on my ignition switch was too much so I installed a relay that switches battery power directly to the distributor when the key is turned on.

Finally after it sat for a week and wouldn't start I left for the autoparts store figuring that I would by what ever performance system that the had in stock. My local Parts + store had a performance aluminum CSI hei that looks exactly like the gm but brand new and at a reasonable price. I took it home and installed it. The truck fired up but it is not running all that well. i notice that the timing light seems to skip some beats. Tomorrow morning I am going to hot wire it directly from the battery and see if that makes any difference.

Anyone else have similar experiences with HEI? This really shouldn't be that difficult but I sure am having trouble with it. Thank for any ideas.
john.