[sick67]

I have no idea what plugs to run. SB400 9to1 compression with cast GM 75cc heads.MSD pro-billet dist.6al ign. I'm an NGK person but any ideas are welcome.Thanks

[maxharvard]

I have run champions the whole time... non platinum and they work great

[sick67]

What's the number on them

[DOUG G]

AC 44 or 45's is all I ran for the longest time(400+.030,9.5:1,stock ported&polished heads,76cc). Now I have aftermarket heads so I need to look at different plugs.

[pdq67]

As silly as this sounds, I always had just a schosh better luck with Autolites in my old motors.

They seemed to be just a bit off one way or the other in heat-range vs A-C's or Champions at least to me?????

Like a 44.5, weird, maybe it's just me?????

pdq67

[Eric68]

Not sure what plug heat range to recommend but I agree with PDQ on the Autolight comment. When I was running them in my 383 they seemed to stay clean longer than the AC Delco's in the same heat range.

Sounds like the AC Doug mentioned would be a very good starting point -- maybe you could have your local parts guy cross-reference the AC to Autolight . . .

[sick67]

Ac 44 or 45 is the actual number?

[dawg]

look into the DESO iridium plugs
they have a chart to convert to aswell.
those plugs are the best there is bar none!
http://www.densoiridium.com/findmypart.php
http://www.denso.co.jp/PLUG/iridium-e/

[pdq67]

Thanks Eric for the back-up..

It's onna those funny things I can't explain???

And when I had an oil burner I would use the extended tip plugs too....

pdq67

[DOUG G]

r45ts or r44ts are the numbers on the plugs.

[sick67]

Thanks

[sick67]

What gap should I run these at. Sorry if I'm being a PITA

[DOUG G]

.035 with points .045 with HEI

[wizard67]

If you are running a blaster 2 coil with your MSD setup i would recommend starting with a .045 gap and maybe going to .050...this will probably open up a whole "nuther can o worms" because everyone does things different but that is what I run and it works great for me!! Now, being winter time I'm running the R45TS AC plugs, and in the summer heat I run R44TS just for peace of mind. I've always had really good luck with the AC plugs, as long as i keep it tuned. Don't worry about being a pain...everyone's here to help out!