What ha v e you folks found to work well with a similar setup? 408 magnum, EQ heads with 2.02 intakes,10.1/1 compression with .039 quench on one side, 15/8 stepped to 1 3/4 headers, cam is a Muthr Thumper with 291/311 lsa107 cam, in at 105. The .050 numbers are 235 @ .050 intake and 249 exhaust, with lifts of (?) .560 and .550.
I bought a new MP distributor, and took a shot at what I hope is close to a good curve. It should have about 18 degrees mechanical advance, initial setting of 16 degrees for 34 total. I messed with the biggest spring so it comes in a little slower due to the short distributor advance and high initial. This is a pump gas motor running 93 BP e10 gas.

For cruising with a light throttle input you
would like more timing.. maybe as much as 45-50*
but thats stuff you have to play with.. for the
rest of the timing your in the ball park except
for when it comes in and how fast it comes in...
if you dont have a dist machine it can get old
trying to get it figured out.. lots of playing

Yeah, lots of playing, I agree! That is one thing that is really nice about switching to EFI. You just type in the advance that you want at each point and it does it. No more screwing around with springs and dashpots and retard modules. I don't think I'm ever going back to using a distributor......

I would try the quickest advancing springs you have after driving it the way you have it now and see which set up you like the best and go from there

After fooling around with light springs to have it all in by 1500, taking all but maybe 15 degrees advance out of it and trying to get a decent idle below 1000 on a lot of this stuff, I get to the point where I just lock it out and stay conservative on the total for putting around on the street. Idles nice in gear with the biggest cams below 1000RPM, nice response, carb's adjusted where it's meant to be. Starting can be a bit of an issue on some, but a start retard and/or electronically controlled advance curve works too.

If it's all in by 1500, the only thing accomplished leaving the advance functional is avoiding the possible hard start issue.

Greg I know my 63 is a different combo and its a bigblock but its a very simple timing curve I run. I got a line on a brand new Mallory race dist when I was putting my 493 together so I bought it real cheap as it had a bad pick-up coil. So I replace the pick-up coil in 2006 when I bought it and its been working fine all these years. Its a race type dist with no vacum advance as its just mechanical advance. So I set it up to have full advance by 1800 rpm which it does. I am running about 36 total which it seems to like best. It has adjustments for the curve but I set my total at 36 and found out at idle of about 900 to 1000 in gear it has about 20 to 22 degrees and as soon as it goes to 1800 rpm its on 36. And to be honest the car loves it set like that with my combo. It always cranks fine even when hot at almost 200 degrees. It never cranks slow and has great driveability like this. Even today it was about 95 degrees but not super humid so it was bearable but very hot as I drove it about 30 miles one way to a car show and we stopped for gas along the way. It was running about 185 to 190 and after a few minute hot soak sitting at the gas station getting gas it cranked over at a normal fast cranking speed when I fired it up to leave. My 63 loves this combo of about 22 degrees at idle in gear and 36 all in by 1800 rpm. No pinging at all and it just goes like mad when you hit the throttle at any rpm. It does have good quench and a Dwayne Porter custom solid flat tappet cam to keep the cyl pressure pump gas friendly. Its such a simple timing curve setup and my car loves it. Ron

If I had thought this through a bit Andy, I would have gone that way after buying a new carb and fuel pump, I suppose I was half way there at least?
The biggest concern I have is too quick of a rate on the mechanical advance because of the small cam/iron head/high compression combo. I will start dyno testing with a little race gas in the mix and time allowing will try strait 93e10 to see how it likes it . Thanks for all the input, folks.

I had the same curve in my 408. Worked great. If i remember right, i used the silver and blue spring in MSD distributor.