Technical Small block Chevy, needing spark plug advise. Thanks!

T is for Tapered Seat, but the S is for the extended nose. I run R44 XLS in my old big blocks, they also have the extended nose, XL means extra long reach, which the early heads used. You can also buy R45T plugs.

here's a comparison, although this is an R45TS vs R44T

 

thanks for the info. I run the R45TS in most small chevys I have run.

 

Just out of curiosity, what is your electrical system voltage at idle?

 

Mad Mike, I'll have to check, but I think it's right where it should be. I'm waiting on sparkplugs from Summit. Should be here tomorrow. I'm going to check the power valve when I change the plugs. I'll be changing the jets too.

 

Just curious, what do the plugs look like?

 

427 sleeper, I'll pull them tomorrow. My new plugs arrived tonight.

 

427 sleeper, here's a picture of the sparkplug. These are the platinum plugs. I put the sparkplugs in it that Squirrel recommended. I also put #66 jets in it, I had #67 jets in it. The power valve is #6.5. I didn't finish putting the carburetor back together tonight, I'll do that tomorrow.

 

I'll bet your part throttle vacuum is right about where the PV wants to open...

 

"T" is tapered seat
"S" is extended tip.
"TS" means it has both.

ACPlugInfo.pdf (toms427impala.info)

 

Any updates?

 

Installed the sparkplugs Squirrel suggested, installed #66 jets. Doesn't smell rich, starts right up and sounds good. That being said, I haven't driven it yet.