Autolite 3910's

Thanks guys. I appreciate all the help. When indexing the plug, the strap should be pointed down correct.

Chris

Correct.

Zip.

plugs
 

i say stay away from champion plugs , bosch arent worth a $hit either i haven't had them last in anything bikes cars, (lawn mowers) ect..
ngk are great plugs, autolite - definitely ac delco

sorry still just a little confussed.with the head off.the gap should be facing the valves or the piston.. :oops:

I index them due to the high dome pistons and i don't want the piston to close the gap up. As you know most high dome pistons have a radius cut in the dome to clear the plug ends, but there is some power gains that can be associated with indexing. i don't know how much but all agree there is some. Indexing also allows for better flame travel, but to answer your question i think the open end should be facing the valves, but not everyone thinks this way. Here is a pretty good article by Autozone, which by the way sells the indexing washers, so does jegs,summit,etc.

JMO

Zip.

http://www.advanceautoparts.com/engl...#Power%20Gains

Bigray, I think it is facing the valve, but double check me on that... it has been awhile.

Am I the only person out there that has fouled Autolite, NGK, Champion, etc... THEN WENT to Bosch "Platnum" & never had a problem since??? When jetting or tuning a carb (such as new one) I will never run anything else... they simply don't foul. I had NGK, & crossed over the correct heat range for my BBC & never had a problem again... they cost more, but who cares. JMO

I draw a black line (permanent marker) on the porcelin where the backstrap is on the plug so i can see where my mark is..i try to get the backstrap in the 12 o'clock position..but 10 and 2 will work...i index for clearance insurance only..keeping backstrap as far away from piston as possible.

Brian

Thanks Guys,
Brian I think you told me that when I was up there last time. Man I can forget things. I guess we are all getting old. :D

Chris

I run NGK B9ES plugs gaped at .035 and I run an MSD7AL3 with a Pro Power coil. Very reliable with no issues.