Stage II head....spark plug reach?????

[buizilla]

Finally getting around to changing the plugs on a car I bought 3 months ago . 274" on-center w/ stage II heads, the plugs I took out are AC R43T .460 reach. The POWER SOURCE BOOK says all stage II aluminum heads are .708 reach tapered seat plugs. Could the previous owner simply have made a mistake and purchased the wrong plug or did CHAPMAN do some serious hogging on the chambers {not likely}. Looks like there is enough threads in the head for the longer plug.

Thanks, Greg...............

 

[Otto J]

Finally getting around to changing the plugs on a car I bought 3 months ago . 274" on-center w/ stage II heads, the plugs I took out are AC R43T .460 reach. The POWER SOURCE BOOK says all stage II aluminum heads are .708 reach tapered seat plugs. Could the previous owner simply have made a mistake and purchased the wrong plug or did CHAPMAN do some serious hogging on the chambers {not likely}. Looks like there is enough threads in the head for the longer plug.

Thanks, Greg...............

They take long plugs,R43t are not long plugs
R43LT are

 

[GNBRETT]

They take long plugs,R43t are not long plugs
R43LT are

Is there anything you don't know?

Btw, my fender cover came in today. It has the "T" symbol on it. Looks pretty good. It's a quality product, I was impressed. She should buy a banner. I'll bring it over tomorrow.

I just saw the Ring post in ur sig...

 

[maverick]

Well all I can tell you is the plugs I put into my buick stage II heads are Autolite AR472.

 

[Chuck Leeper]

If the engine has miles on it, w/ the short reach plugs, there's a possibility that the threads are dirty at the chamber end.
I'd be REAL careful w/ new plug install. If you can't screw them in all the way, by hand, I'd be cleaning the threads first.