Does anyone make a 5/8" hex, gasket seat resistor plug for our engines? Seems like someone posted a list of plugs and the specs for them not too long ago, but I've been searching and can't find it.

Thanks,
AV8TOR

Champion used to make one with a flat aluminum gasket ring, not a crush ring. A 5/8" hex, 14mm tapered seat plug can be used and will seal in place of the bigger 3/4"-13/16" hex 14mm plugs.

<hr />AV8TOR, I am sure I seen that list just a few days ago....you know what...I cannot find it either! Capt,n

Several makers, Champion, NGK, Denso, Autolite, Bosch, do them. It's just a matter of determining reach and heat range and consulting their part number charts. I consider a crush ring a gasket seat, so forgive me if that's not what you seek.

Thanks for the replies. I tried researching by plug construction and couldn't find one with a 5/8" hex and a crush ring or gasket seat; only in a taper seat. At least in the short reach as used in our engines. www.sparkplugs.com is a pretty good site for researching spark plugs. Oh well, I was hoping someone knew of one. Looks like I will have to machine the heads for taper seat, or buy other plug caps for the RCEXL ignition I have that is for 5/8" hex plugs. (I know taper seat plugs will "sort of" seal in a gasket seat head, but it is a bit questionable. Better to machine a small taper.)

AV8TOR

The only 5/8" hex I have found with a crush ring has 10mm threads.

Milton