Wenzler Series 2 Heads - What spark plugs did you use?
 

They are certainly a longer reach plug than the standard factory plugs. I can probably take a guess, or take one of the heads into parts store and match something up. But hoping someone here who has successfully used the Wenzler heads would share what plug they used. Thanks!

A more important question might be what heat range you need in whatever brand plug you use which is determined by how much HP you think the motor will make?
I have ported 2 sets of these Heads and the 288 Intake cfm that they are said to flow out of the box was not showing up on my bench with both sets of heads!

Let's say that things have changed and they do now flow 288 out of the box and let's assume your running enough valve lift to average 275 cfm out of that 288, so 275 cfm could make you 565 hp in a well thought out motor and in terms of a AC Delco brand plug I would start off with a plug of a 42 heat range with a extended tip for a base line.

Once you determine what you need for basic dimensions on the spark plug I may be able to help. If they are indeed 3/4" reach, 5/8" hex, gasket style plugs, I have a large selection in Autolite, Champion and NGK I can fix you up with. PM me or give me a call if that is the style they use.

I understand all of that about the heat range, etc. What I'm looking for is a part number so I know what reach I should use. A quick glance looks like they are tapered seat but certainly a longer reach than say a R45TS. I can figure it out, I was just trying to take the lazy route.

I used Autolite 3924 or 3923 when I ran those heads.

Thanks Mike. Yeah I've never run these heads before so I was just looking to see what style others have used before and then play with the heat range from there, probably staying on the cooler side. Having just taken a quick look they appear to have a tapered seat to me, but I've been working on other things trying to get this ready for Norwalk. So I could be wrong about that, I'll have to take a closer look. One head is still off the engine so it really won't be hard to make sure I have the right length, etc.

Thanks Jack!!

My Wenzlers were series one I think. But the previous owner was running Autolite AR473 which is a really cold plug. I went with a R5724-8 or # 7317 NGK. These were a little hotter. There's not not much to pick from that I could find anyway with those dimensions.

I ran AC R44LTS6 in my Wenzler (series one I beleive) heads. Tapered seat, long reach, extended tip. Seemed to work ok in my pump gas 462.

I currently run the Series II and use NGK R5672A-8 plugs.

Thanks for all the responses guys.

I'm starting to question whether these are series 1 or 2. I was told these are 2 but mine have a tapered seat for the spark plug. From the responses I've gotten it looks like series 1 was tapered and 2 has a gasket seat. Any other ways to tell?

My II's are gasket. Call Larry and he may be able to tell you. KRE was a distributor, they may offer insight as well.