Help! Heads and plugs options

[CsR41]

So I have a 355 with Pro Topline heads(like RHS?)

With the lump that I have on my pistons, I need a recessed spark plug(retracted gap plugs I think they're called??) and NGK can't seem to find anything close to what I need.

My thought was to get a 3249(short reach) and use indexing washer to back it up just enough for clearance.. Has anyone dealt with this? I'm really confused on what else to do!

Thanks.

[dereksehi]

I have installed those heads before with a dome also I would use an AR134 style plug they dont have the extended tip and will clear a dome.

[CsR41]

Dereksehi, I just don't see how any plug with an external tip will clear. I had to clearance the head to even keep the piston from contacting the area below the spark plug.

the pistons im using are the JE 11cc dome with the 64cc(cut to 62cc).

[js11]

Sounds like you have limited Piston to valve clearance (PVC) ... and then some. I think Dereskehi said to not use the extended tip Plug. I agree. With limited PVC extended tip plugs could give you problems. I know a few folks who have mistakenly used those and had clearance issues (myself included). Also, are the pistons notched for clearance? Another thing to consider is that you may have to use a thicker head gasket, if you haven't already done so. You don't want to index the plugs back too far either, which could cause other problems. Just spit-ballin' here.

[CsR41]

Well, I used the ngk 3249 plug and with it backed out 1 full rotation from seated everything is OK.

Plenty of head to piston and valve clearance now. Just gonna hope and pray no other problems!

[dereksehi]

Do you have the correct pistons for that head they take a dome that is scalloped per say to clear the head and the plug better a conventional sbc dome wouldn't clear. The dome should be shape like a Keith black IC760 to properly clear these heads and plugs.

[CsR41]

It is slightly, yes. This is what JE told me I needed to run with this head.