452 head spark plug help

[PRHeads]

I have some 452’s here with the bump, but it’s machined out so a normal J series gasketed plug fits no problem.

It would seem that the heads where the bump hasn’t been partially machined away(and have no gasket sealing area) are the ones that use the tapered seat plugs.

If a J series plug won’t fit, use a TS plug.

452 for TS plug-

 

[khryslerkid]

I have some 452’s here with the bump, but it’s machined out so a normal J series gasketed plug fits no problem.

It would seem that the heads where the bump hasn’t been partially machined away(and have no gasket sealing area) are the ones that use the tapered seat plugs.

If a J series plug won’t fit, use a TS plug.

View attachment 1962971

Would the bump also allow more material for the drilled coolant passages. Machining them for the larger plug might not be a good thing. One might think the drilled coolant passages were created for the fact that motor home engines create more heat being stuffed under that dog box.

 

[PRHeads]

Machining them for the larger plug might not be a good thing.

The factory did the heads I have here.

 

[PRHeads]

Looks like the OP had settled on NGK “5” heat range.

The short reach gasketed plug in that heat range is an XR5.

 

[khryslerkid]

Looks like the OP had settled on NGK “5” heat range.

The short reach gasketed plug in that heat range is an XR5.

It's what I'm using in my 452 heads.