If you own a Turbo III powered vehicle there's about a 99% chance you are aware of the fact that Lotus used a steel plug in the aluminum cast head, and you are likely aware of the issues associated with that engineering mistake.
 
These RDI Performance core plugs are made from 6061 billet aluminum and will ONLY FIT the factory replacement DUNN turbo III heads that Chrysler used after their initial run of heads ran out. 
 
 How can you tell which head you have?  Look on the passenger side of the head (you will have to remove the upper timing cover to expose the casting area just below the cam sprockets) and if your head says "DUNN" then these are the plugs you need to keep your head from cracking.
 
If your head does NOT have the word DUNN cast into it, then you'll need our other (early/production) aluminum plugs also listed in the Turbo III section of our website.    Price is for a full set of 3 plugs (i.e.  enough to do 1 head).