Setting the timing on a 69 318

Based on what you've written, No. But really it depends on the curve in the distributor.

Look at the timing graph I posted above. Notice the CAP distributor is set at 5* After, while the other at 5* BTC. Yet they end up at pretty much the same place by 1400 rpm. Now lets say you've got the original CAP distributor; setting the initial timing at 5*BTD at 550 rpm is 10* more than spec. This will will add 10* everywhere and it will ping under load.

Kind of a slippery slope talking about the CAP specs. Unless his car was built in LA and still has the original distributor, let's not get side tracked. The CAP specs were just for emissions and made the cars run like crap. LOL