I'm putting a 1969 El Camino 350 HEI distributor in my 265 but don't know the El Camino's timing. Does anyone know it or know where to see a free online repair manual for the '69?
I am relatively sure the timing was set around 6-8 deg. before T.D.C. You can more likely set it at 10-12 deg. with no problems, remember to disconnect the vacuum advance and set your static timing with the points on the tone ring lined up with the reluctor. That will get you close enough to start it. Don't forget the H.E.I. needs a full 12V key on at the BAT. terminal. If your car had a ballast resistor/wire you need to remove it or find another source for 12V in the run and crank positions.
Not to get picky but, the 'model' of distributor you use would have no bearing on the static timing of your engine. The timing spec for a 265 would remain the timing spec for a 265. Any of the above settings will work but what you really want to know is the TOTAL timing and rpm level that it should be "all in". If its a stock 265 you should be able to get away with 34 degrees, all in by 2800 rpm. After that is set, then hook up vacuum advance.
Yes, the total timing is what is important, but it's probably not very different between engines...while the initial timing and advance curve varies quite a bit for different distributors. So my guess is that by using the 69 specs on a 69 distributor in a mid 50s engine, 402 will get it pretty close. Some tweaking required.