Hi,

I'm doing the tune-up thing this weekend and I've got the following MSD Ignition parts going into my stock 305 TBI with open element air filter.

MSD coil # 8226
MSD cap # 8426
MSD rotor # 8427
MSD super conductor wire set # 31839.

This being a tad hotter than stock ignition set-up I was wondering which type of plug to use.
Not name brand.... but should I use a hot plug or a cold plug?

I did some reading in my Chilton manual and it really does not give too much info on the plugs to use. It just says that a cold plug could lead to carbon and oil build up and cause the plug to misfire. While a hot plug could have too much heat and cause pre-ignition causing pinging. This all depends on driving conditions of course.
Well, we do both stop and go driving and mountain driving and highway driving. I really don't want to change the plugs prior to going to the mountains for the day.

I really don't want to resort on the autozone counterboy who has the Honda sitting in the parking lot who's rear fin takes up two parking spaces to tell me which plug I should put in my V8.

I'm kinda thinking that I should go with a colder plug since I'll be pushing more juice to the plug.
Hot ignition and hot plugs makes me think it will have big time pre-ignition problems.

I'm also thinking timing has a ton to do with this as well.

Also,

Where should I gap these plugs. Stock is .035 and I've been hearing up to .045 for hotter ignition set-ups. But then again, if you have a colder plug would you not gap it wider than a hot plug??
Thus having a cold plug with a wide gap would cause more of the fule/air to ignite reducing carbon/oil build up.

I'm pretty sure I'm way off base on some of these ideas because I don't have a clue when it comes to spark plugs. That's why I'm asking these questions.

Again I'm not looking for brand names here, just looking for the right plug.

For those who can provide some part #'s along with their answers, I greatly thank you in advance.

 

i'd start with 1 or 2 ranges colder and see how it works

 

Your right, you don't have a clue about sparkplug heat
range selection. Use the stock recommended plug for that
stock motor. Be sure to gap the plug to the stock spec.
Flipping the aircleaner lid and installing a Msd distributor cap
will not change the plug heatrange requirement. Good Luck

 

i second ede, it's best to start with a colder plug and move up a heat range if they foul rather than use what's 'recommended' and kill your engine with preignition or detonation. fouling will not have any permanent effects on an engine.