Help needed

[shagmebaby]

Just bought my 1st Boat, 79' Nordic 22. She's Clean runs ok. The SB 355 is fresh w/ "mild" cam. Im looking to upgrade the Ignition to a Performance Dist. DUI HEI . But Im at a loss for Carb ,Intake & the right plugs for a boat. Ive been around plenty of SB's but on Alky. and never in a boat application. Any help appreciated.

[SmokinLowriderSS]

Just run stock small-block plugs. I don't have numbers but have a 70's corvette looked up at whatever parts store and start with mid-range.
I'm not used to tuning a small block as I'm wheeling a 454 but Carb, I'm a Holley fan, something arround 600CFM would be solid. Vac secc for better driveability & mileage, Mech Secc for a little more muscle (Vac Seccs ARE tunable for opening if you weren't aware).
Intake, I don't think you can go wrong with a Performer Dual Plane from Edelbrock. The Air Gap & RPM serieses are plusses IMO(I'm really happy with mine).
Ignition, just stay marine if you have an enclosed engine bay. (Now I'll open the worm bucket & pour). I'm not the biggest believer that you will see anything like increased power from an ignition change, (regardless of what someone's advertizing says) so don't expect one. Reduced maint, yes (although I see a lot of broken MSD boxes on here for reasons I do not know and won't speculate on), easier starting, maybe (only if your current ignition is in bad shape personally).
I'm still running my original 1978 Prestolite marine distributor in my 454, single points (yes, changed a few times since '78 along with the other maint parts). My Taylor is cold-blooded when cold but I am not running a choke of any sort. Once warm, the motor seldom even makes a full-spin before lighting.
There's my $.02. Best of luck to you.

[shagmebaby]

What's your take on the Davis Marine HEI ? There is no hi fire box but still 50,000 volts.

[Sleek-Jet]

What's your take on the Davis Marine HEI ? There is no hi fire box but still 50,000 volts.
It's a good unit... don't change anything as far as ignition goes. :D