in search of better spark plug

[johns67cougar]

Hello everyone nice to see such a active site. I have a 91 mustang conv. with a 347 storker and a vortech supercharger @10lbs. of boost. and all the other goodies to make close to 500 horses at the wheels done by Lamottas in Longwwood, Fl. The plug they put in is a autolite 3923 gap @.32. I've put about 15,000 miles on this setup. What are some of the plugs you guys are using. I feel theres must be a better plug for the job. The ing. setup is all msd.Open to any input.

[lafinrat]

I haven't been able to get any of the Autolites to work well lately. Buy NGKs. You need a 4554 (HR 8) for street or 5238 (HR 9) for extended high speed operation. Try the latter first.

[91gt347]

Yep. NGK's bro. Autolites work well on a N/A mild 5.0. Some dont have any issues with a setup like yours. I know on my dads car (My old car). Running NGK's on the bottle made a world of difference.

[poneyexpress]

I believe NGK's are what kenne bell recomends on their web site also .

[Screw-Rice]

I have used NGK's on everything I have had over the last 5 years. Figured if they were good enough for my old instructors 9 second Super Bee they are good enough for my applications, ha ha.

[johns67cougar]

are the ngks you advise for a blower setupand colder set of plugs then factory. non resistor over resistor? noise interference on the radio?? just trying to learn. thanks

[lafinrat]

Originally Posted by johns67cougar

are the ngks you advise for a blower setupand colder set of plugs then factory. non resistor over resistor? noise interference on the radio?? just trying to learn. thanks

The heat ranges listed are what you need for your application based on your original post. They are colder than stock. NGK heat ranges go up in number as they get colder, with 10 being the coldest. The 9 might be a little cold for you, but it's better to start out cold. If they don't foul, you're good. If they do foul, put HR 8 in it.

Those are non-resistor plugs. You shouldn't have any noticable radio noise. I use those plugs in cars with pretty sensitive electronics and no RFI issues.

[johns67cougar]

Thanks alot. I'll be putting a set in this weekend.
This site is great along with the people in it. Keep on motoring.

[SpdBoss]

NGK's all the way

[lafinrat]

Originally Posted by johns67cougar

Thanks alot. I'll be putting a set in this weekend.
This site is great along with the people in it. Keep on motoring.

Glad to have you here.

I just remembered, the Camaro I just drove 1000 miles had the HR 8 non-resistors and the radio, along with everything else, worked great. Hope that helps.