Try 25 initial, 35 at WOT and then layer in 6 degrees of vacuum advance on top of that. You'll have to drive it to find out what it really wants but 31 total isn't enough with the Indy heads. Those will want at least 35 and maybe more. Idle timing is the easiest to sort out since you can just change the timing in your driveway and see what works the best. With a big cam you usually want as much timing at idle as possible.

Does your system have a built in start retard? Holley EFI always starts the engine at 15 degrees and then it pops up to the idle timing. Check to see what yours does.

This is what I run, 512ci, 255,258 @ .050 cam, Hilborn EFI, you will need to tweak it some

Thanks Andy! I had a feeling the timing was to low, the engine has more to give.
I will try it. Do you have any guess of at what rpm i should give it full advance? From what i have read many brings it in pretty early.

Start with 3500 for full advance and try it. You'll just have to play around with it since it all depends on how heavy the car is, what the gear ratio is, etc. No way to give you an answer without knowing all the details so just try it and adjust as you need to.

Thanks Andy! I know its difficult to give an answer of a timing curve, now i have a starting point. My car is quite heavy, its a Chrysler 300 -64 2 door hard top. The cars weight is 4189 lbs, rear wheels 275/60-15 with a cicumference of 27.99", gear ratio in the rear 3.55:1, its a 8 3/4 with a eaton true trac helical diff, 3" drive shaft with 3150 universal joint front/back, 727 tci streetfighter with a reverse manual valve body, 9.5" 3000 stall custom built converter. I have eaton custom made super stock leaf springs, adjustable pinion snubber and i actually have good traction with this car, when i hit the throttle the car sits in the back and throw away this heavy car like a bullet. The engine answers amazing but i have had a feeling that i have been a little to careful with the timing.

On my last pump gas street and strip motor 517 C.I. stroker (727+ HP on pump swill at the flywheel) I recurved the stock distributor by welding up both advance slots so it had 16 crankshaft degrees (the distributor had 8 distributor degrees in it) total mechanical advance and set the initial timing at 14 degrees before top dead center and ended up adjusting the distributor to have 34 degrees total at or before 2000 RPM by using the Mr. Gasket 925 B advance spring kit for Chevys
That worked very WELL on the street and at the track.: up:: scope:

Mine, 10+ BB stoker motors, were all in before 2000 RPM on several different race and pump gas street motor using the MSD race boxes, 404B, 7 and 7AL2 boxes . The Duster converter world flash between 4300 and 4600 depending on the weather and track elevation so all the timing was in long before those RPM were reached
I did get one of my pump gas street motors to ping on Oregon 91 octane non ethanol pump swill back in 2009 by having the total timing set at 38 BTDC and using very light throttle pressure climbing a steep grade in the middle of a summer day here in central Oregon, it wouldn't ping at 36 degrees BTDC: work:
I've done a bunch of engine tuning on engine and chassis dyno as well as at the tracks, BB Mopar's on gasoline seem to like 34 to 36 degrees total advance: up: Not 33 and not 37 BTDC
You need to verify the timing marks on the dampener and TDC on the balancer and the timing tab on the timing cover to make sure you're getting the correct readings: scope:
One really good west coast division 7 SS racer had a motor built by a shop that had used a early timing cover with a later model year balancer, that made him think that motor liked 42 degrees total timing
It didn't when he got the correct timing cover on it the next year, the early covers have a straight steel tab for the timing marks with zero at the top of them. The later covers, maybe 1967 and later, have a curve timing tab with TDC in the center of the tabs

I use performance trends engine software for all the engines I build. If you put in good numbers you get good results. I also have an engine dyno, and again if you put in good numbers the predictions are very close to real world. The program also generates an ignition curve, idle vacuum, cranking compression, and lots of other parameters. I have taken the advance curve the program generated and used it in setting up fuel injection tables as well. It worked great. Timing advance is not that much of a black art. You need advance because fuel burns at a constant rate, so as engine speed increases you have to fire the mixture sooner so it has time to burn. couple that with rod stroke ratio, octane, cranking compression, and a couple other variables and you can calculate it pretty close.

Mine, 10+ BB stoker motors, were all in before 2000 RPM on several different race and pump gas street motor using the MSD race boxes, 404B, 7 and 7AL2 boxes . The Duster converter world flash between 4300 and 4600 depending on the weather and track elevation so all the timing was in long before those RPM were reached
I did get one of my pump gas street motors to ping on Oregon 91 octane non ethanol pump swill back in 2009 by having the total timing set at 38 BTDC and using very light throttle pressure climbing a steep grade in the middle of a summer day here in central Oregon, it wouldn't ping at 36 degrees BTDC: work:
I've done a bunch of engine tuning on engine and chassis dyno as well as at the tracks, BB Mopar's on gasoline seem to like 34 to 36 degrees total advance: up: Not 33 and not 37 BTDC
You need to verify the timing marks on the dampener and TDC on the balancer and the timing tab on the timing cover to make sure you're getting the correct readings: scope:
One really good west coast division 7 SS racer had a motor built by a shop that had used a early timing cover with a later model year balancer, that made him think that motor liked 42 degrees total timing
It didn't when he got the correct timing cover on it the next year, the early covers have a straight steel tab for the timing marks with zero at the top of them. The later covers, maybe 1967 and later, have a curve timing tab with TDC in the center of the tabs

I'm under the impression that the new MSD grid box won't fire the coil, coils until the starter makes 2 complete RPM, is this correct?

I
I'm under the impression that the new MSD grid box won't fire the coil, coils until the starter makes 2 complete RPM, is this correct?