On my 10.75:1 451 with 262/266 @ .050 camshaft, I have a regular mopar perf/OE style distributor
and all I did was use one spring from the Mr Gasket 925B kit. No tricks are done with the advance plate, etc.
I run 34 to 38 total all in at idle which is typically 1100+ for valvetrain oiling purposes, and there is about 20 or 21 degrees in the plate so the advance mechanism
which only acts as a start retard.
I've been doing this since the '80s on most with big cam combinations and it seems to work fine for me for street/strip purposes.
There is probably additional driveability improvement to be found in working with the vacuum advance, but I never took the time to experiment with it.
Pretty much identical to what I have done on mine. 38 is the limit with good 91 no ethanol I'm at 10.6:1 CR. I now have an add-on timing adjustment knob from MSD that allows me to take timing out from the drivers seat for varying levels of nitrous.
Is there actually any pump gas without ethanol today? Here in Sweden you cant get any pump gas without it, we have 5% in all gas, 95 and 98 octan, i belive its same your 91 and 93 octan and the rest of Europe have 10% Ethanol, maybe you are lucky in the states. I have a 493 cui stroker, 10,04:1, xe275hl camshaft 231/237@050, dynamic comp 8,03:1 with Edelbrock e-street 84cc heads, i drive it on 98 octan( same your 93) without pinging with a Fbo distributor 18 initial and vacuum takes it to almost 30 at idle on 900 rpm( manifold vacuum) and 34 full advance at 3200 rpm. The engine running great with a huge low end, really nice on the street and without any pinging what so ever.
