Lock the timing at 34 degrees and let a Daytona ignition box do the rest.

Youd sorta think that BUT I will say, a stock 500 efi with slightly less compression and cam has 35.9 degrees of timing from factory from 5000 up. On subject of midrange timing, , i have often found more tq (and less KR) from ramping timing up until max is past the tq peak vs light springs and co,ming in early.

I'm no expert at all, though on my 42’ sportfish considering the heavy load these engines endure, have always set timing at 34 degrees “all in” just to be safe.

If I get 1,000 hours without any big issues, I’m pretty happy.

Latest build engines are on pallet waiting for install, very similar to OP’s. ZZ502 short blocks, AFR heads, FWC and Holley HP already installed.

Distributors are Delco small cap EST. Fully programmable when connected to HP, and have default curve when not.

so what is the boat? big heavy sled or small light cat? one can tolerate more timing earlier vs the other. at 9.2 with iron heads I would lean towards 32-33 total as you never know just how good the fuel you get really is, but that is just me.

That’s where I was going with what I said above.

Pretty much what I’m running in the 311. Testing this past weekend trying to get the fuel right… really loved 35 degrees and the ESTs are throwing 30 at idle.

The boat is a 1996 Baja 252, the exact weight I am not sure of but I would say its no light weight. I know my buddie runs upwards of 41 degrees but in a 1972 Nova and cruises on the street at 36 degrees but again that's a car where it is not always under load. I'm sure a boat is a totally different animal.

I have Holley HP for it to be installed in the fall but for this season I want to get it dialed in on a carb. This boat is on a small lake, I mean SMALL! so long periods of WOT doesnt happen and a cruise around the entire lake at 3,500rpm is 4-6 minutes lol. The shoreline is 7 miles but I want to know the boat is running at its best but in the safe zone.

I think I will go to 34 degrees and all in at 3-3500 I would assume that is the area of peak tq on a big block?

Why does it matter iron over aluminum heads? Iron holds more heat?

This is the advice I followed.

iron heads hold more heat and are thus more prone to detonation as the compression ratio goes up. aluminum sheds heat faster and so you can run the compression ratio up higher with less detonation risk. 9.2 to 9.3 is considered to be about the max for iron heads in a boat due to the load and at that level you need to run 91 to 93 octane but as I said you are assuming that what you get is what you paid for as far as fuel quality.

I'd be all in at 3000 or just after and total at 35 degrees. Run the tightest curve you can as long as initial isnt to high to generate hard starts. If thats the case add curve and pull base to be all in at similar point but total is more critical unless you idle or troll the bulk of your trip.