Engine kit type?

the head will work, but you'll need to space out the mounting holes wider. I run one and it works alright. I dont know about the hi-hi head, but the 70cc hi comp isn't really all that much of an upgrade. I've been considering switching back considering you need to grind the cooling fins to allow space for your 14mm socket (even a thin one gets jammed, its frustrating). I dont even run a headgasket, I find with the puch head they leak too much so I use permetex copper, but some have used 2 gaskets, but honestly I think the stock head is just fine, just watch the temps really.

the puch heads are the best bang for your buck, but you may end up needing to run 2 head gaskets according to some. If you want good compression out of it you'll want the hi-hi head. As I said I didnt notice any more power, but with these motors you tend to get very little per aftermarket part, but altogether they can add up to alot. The aftermarket heads specifically designed for these motors are pricey IMHO, they probably provide better cooling but as stated I believe the stock head is just fine, just sand it down 1mm or so, and it should net you ~125psi compression. If you have a torque wrench, use it, 120 to 140 in/lbs. I picked up a cheap one from Peavey Mart for $30 that isn't ridiculously long or high torque (there's one at Canadian Tire for $30 as well but it's huge and reads in huge increments [like... 80 ft.lbs]. These motors only need 10-12 ft/lbs (10 ft x 12 inches per foot = 120 ft lbs)).

If you're set on an aftermarket head, then by all means get the puch. If you dont have a way to modify the mounting holes at all, then perhaps an Arrow or Dax head (just a stock head already ground down)