Mopar Muscle Association UK

Removing the old ones; get an old flat blade screwdriver and hammer it into the core plug and lever it out. Replace with brass core plugs, available as a set from WASP. When replacing them, first clean the hole with some emery paper, smear the edge of the plug with a bit of hylomar or rtv then hammer it in with a suitable size socket. Don't use a socket that is tight in the plug cos when the plug is in, the socket will be wedged in the plug.......Not sure if the core plug set from WASP has the ones for the cylinder heads as well. Good Luck, fella!

Here ya go

http://www.waspspeedshop.com/

In stock here in brass

£18.50 inc vat, £1.85 postage

Ive got loads of them let me know what size you need,
or do you want a complete set, i think I've got a set of steel ones,
if thats any help