FYI, I used a "Dave's Small Body HEI" which has the stock appearance but supplies one heckuva spark. Pulled a plug recently and it was perfect. I ordered and bought mine from Dave in person before he relocated to NV permanently, but I think you can order one (you will need to supply the core and detail your requirements to him before he will start work). Cut and paste the qute above into Google, should come right up. Well worth it, been really happy with it (a specific coild will also be required). I had problems with the first two generations of Pertronix.
JB
JB