i just noticed something. i was looking around e-bay and i found an older used volcano sv. it says that it has only been ran twice, but the engine needs a new piston and sleeve. looking at the cooling head (it's a vx-18 with the blue head) it appears to be really short, like there is very little space between the fins. the stock air filter housing is taller than the cooling head. i swear that i only counted 6 cooling fins on that head. (unless i mis-counted)
maybe this is one of the heads that you are talking about wade?
the head on my vx is taller than the air filter housing, and there appears to be alot more space between the fins..plus my head has 8 cooling fins.
maybe my eyes are playing tricks on me, after all i'm looking at a pic. and sometimes it's hard to get the full perspective from looking at a picture.