Hot news from Steve Davis at Performance Distributors. Now there is a HEI style mechanical advance option with gear drive for old style (GM small block only) tachometers !!! Steve is the guy who will build us a custom curved marine distributor for a Ford 427 marine reverse rotation motor, and I am running three of these on 427 motors now, and one on a small block Chevy 327F clone. These are HEI style 50,000 volt one-wire hook-up units, and they are dead reliable. Spark plugs can be gapped nearly twice as wide as the original spec, as I am running .055” on the 427s instead of .027”, and the motors have not missed firing a cylinder in the years after these units were installed. They are far superior to the old style crab-cap style distributors, and I consider this not only a convenience but also a big safety factor, especially when I am out on the Cumberland River shipping channel at night with a boat load of guests returning from a waterfront restaurant.
If you have a 427 and contemplate installing one of these you will need to use an electric tachometer like I do, and please send me a private message and I will help you with some details. The closed cooling systems are a bit easier than the standard cooling motors, but both are really pretty easy. The 427 carb throttle plate needs to be contoured and a water fitting needs to be rotated and re-plumbed on the standard cooling motors. 427 reverse rotation distributor gears are no longer available, so you will have to send Steve your old one and he’ll just install it on the new unit. Most of the SBC motors take a standard rotation gear whether they are reverse motors or standard.
The hot news now is they will build one with a mechanical tach drive. In order to be sure one of these will fit our boats, I would suggest sending him your old distributor and he’ll send you one back that will be an exact fit and be sure the threads, etc., on the tach drive will mate up properly. Beware there are clearance considerations with some motors like closed cooled Q small blocks.
I know the boat show guys won’t want to see a modern distributor in the engine room, but I can safely testify that these are far superior to the old units and they run great, so we have the choice of originality and pain, or a modern upgrade for happiness and safety. Here are a few photos, and a link to more details. This is only one link like this so if anyone needs help send me a note and I’ll try to hook you up with something that is specific for your application.