Hi
Couple of suggestions When putting in the distributors for the first time set the timing to ZERO. Now using a timing light get the timing at 750, 1000, 1500, 2000, Now it gets scary>>> 2500 and finally 3000 rpm. Do not hold the engine at the higher RPMs for very long, 5-8 seconds. Helps if a Bikini clad helper watches the tach and tells you when to read the timing marks. Write them down. Do this for both engines, they should be withing 5%.
If the max advance in the distributor gives you say 16 degrees, then set the base timing to 6 degrees, which is what most low compression 440's like. Then the 6+16 will give you 22. A bit low but safe for your first run, better less advance then more. If the engines do not knock set base timing to 8 degrees and try again. If it does not knock your good. Do not go above 8 degrees with 87 Ethanol or it may have trouble starting. 440's really want 28 degrees total advance on a stock 8:1 low compression marine engine. The 72 and earlier engines are almost 10:1 and use 24-26 degrees. The higher compression burns the fuel faster so less advance is needed.
You will find that the hot 12 heat range plugs will cause it to knock under load. These engines use 10 range with 87 Ethanol, however Rj10y is no longer made. I have done a lot of testing with many manufactures of plugs and their equivalent to the RJ10Y, but most are just replacements for the RJ12Y. The 825 is a RJ4, a much colder plug and will not pre ignite even under the meanest loads with E10 fuel. I use these in my 426 Wedge Mercruiser Bravo and my twin 440 Magnums in my 33 Searay, as well as the 440 in my 1990 Ramcharger I drive everyday.
Better starting with a colder plug then go hotter. After a lot of testing with various conditions I found the 825 plugs and 8 degrees base with 28 total advance and you will be able to run regular E10. Easier on the wallet.
Remember when starting out setting up a new marine engine start with less timing, colder plugs and a slightly richer mixture. If you are good with the way the carb runs now then you just need to sort out the ignition, easier.
I am not sure what the new Mallory distributors are using for an advance if they say it will work in both directions, as weights are directional. turn them the wrong way and it will not advance. You should get the type of module required from them. Most new distributors have the module built in and you just fire the coil from the distributor, no ballast. I run a fully adjustable pro comp distributor so I can set the max timing and when I want it to come in. You can dial in the curve as well as the max timing. It has a module built in and fires the coil. I will be removing them all this year for the distributor less system I put together this year.
Once we set up the new MPI injection system I will be posting some cool pics and specs. It is a 440 with a distributor less ignition with multi port injection and knock sensors on each head,, laptop tunable, center riser aluminum manifolds, closed cooled and weighs less than a 318.
Good luck.
Dan
