Another sparkplug question

[steveyb]

whats the best spark-plug to use in a 1300sb and does anyone have any ideas what boxes came with what diffs? and what diffs works 1300 rally cars were fitted with? just curious.

[Novasport]

Diff's were all the same in the small block boxes, the final drives differed and can alter the gearing to the purpose you require.
Rally cars are/were usually fitted with plate type LSD's but a Quaife ATB torque biasing diff might be better for road use.
Sparkplug wise, if the engine is standard just fit a standard decent brand like original GM, Bosch or NGK etc. You could probably uprate to a four prong or iridium plug.
You would only need to alter heat range if it was highly modded IMO

[Adam]

Four prong plugs are no upgrade. Just stick with single prong ngk's

[steveyb]

thanks for the reply's, its not standard i just hear a lot of "never use NGK" or "use iridium" etc etc so thought i would ask, and as for the diffs, i actually meant final drive ratios, but thats been answered too, many thanks again.

[marc69]

I use Champion plugs, I had a bad experience many years ago with NGK overheating and not firing correctly in an ohv engine. I would assume NGKs would be fine in an ohc as it is a more modern design and with electrinic ignition will be more accurate then old points etc.

[mowgli]

on my old carb smallblocks, i used gm plugs, they are cheap enough, and when i tried champ & ngk, they didn't last as long.

[Novasport]

I have GM plugs fitted to the Sport as I get them cheap from work. They are just rebranded Bosch plugs iirc.
I have NGK Iridium plus in the 888 and it does smooth it out. I cannot comment on longevity as I change them every three or four years(1500 miles if I am lucky!)

[MK999]

NGK Iridiums last for years, I know of a set that were in a 230bhp 2.0 16v, and now live in a 106 GTi 18 months later.