Well I have just about finished this custom head for my norvel, It is 5 fin like the (oh god can I say It) cox texaco which I always used on my high nitro runs but at ten bucks each I wanted something that would take a short std. plug, so I came up with this, It will take a stock Norvel plug also the custom adpt. has the shape and volume as a cox high comp. hd. and can be either high or low adj. for comp. pic. shows the 3 fin stocker to the right, and the fins each have more area on then,