what spark plugs do you use in your a14 and why?
I wanna have a look at alternatives.

I use BP7ES NGK's

Normally you would run bp5es, it's the standard plug and not necessarily ideal if you're trying to make power because it doesn't transfer the heat into the head fast enough like the 6 and 7 even moreso. I haven't run my motor yet but I was going to run the 6 after a week or so depending on how it's bedding in and tuned etc

Champion RN12YC, because I had two sets left over after I sold my GM V8 5.7 liter. The standard plug specificed for A14 is RN101YC and option is RN12YC, so these are one heat range hotter than standard. After two years, no signs of overheating plugs or any sound of detonation.

BP7ES is two heat range colder, probably work good on a racing engine, but too cold for a street A14.

BCP6EVG for me, colder range for the tuned motor, V groove for nicer spark.
and smaller hex just to be different.. :)

Factory specified NGK BPR5ES is now NGK 7734





Of course you don't have to buy NGK brand, any equivalent plug will suffice. And for you junkyard scroungers, many 4, 6, V8 and V12 engines use the same plugs (US-model vehicles:):

Aston Martin: 79-89 V8, Lagonda, Virage, Zagato
Audi: 1980 4000, 73-79 Fox
BMW: Many models, 1968-1985
Dodge Colt 1974-1975 (Mitsubishi Colt)
Geo Tracker 89-95
Jaguar: many model 1960-1987 (V12 and 6 models)
Land Rover: some 1987-2002 models
Lotus Elite 1976-1979, Esprit 1976-1982
Mazda: 1979-1985 GLC (Familia 3), 79-87 626, 79-84 & 86-87 B2000 pickup, 87-93 B2200 pickup
Mercedes-Benz: many models 1973-1991
MG: 62-66 Midget, 75-79 Midget
Nissan
B110 1971-1973
B210 1975-1976
F10 1976
2000 Roadster 1968-1970
200SX (S110) 1982-1983
720 pickup 1981-1986
D21 (Hardbody) pickup 1986-1989
Pathfinder 1987-1988
Van 1987-1988
Porsche: 78-79 911, 78-82 928 V8, 83-84 944
Renault: 83-87 Alliance, 84-86 Encore, 80-83 LeCar
Rover 3500 V8 1980
Suzuki Samurai 86-95, Sidekick 89-95
Toyota 4Runner 85-88, pickup 85-88
Triumph: some 63-81 models
Volkswagen: Most watercooled 1974-1980
Volvo 760 1984-1990
Yugo: most 1986-1991 models

what size should I set the gap to on NGK BP6ES?

Depends on what ignition?

Stock A12 with points I use .9mm for a nice smooth idle.

1.1 with elec ignition.

Wider gaps burn better -- if the coil can support it. Pre-electronic ignition coils can only do 0.035 gap (0.8mm) . Nissan specified 0.031 to 0.035 inch. For normal use, 0.035 will give a smoother running. But for high RPM, high load use, you migth try 0.31 inch so that the coil is not overwhelmed.

br8eix-11 'iridium' coz I got'em for nothing.