David Hill wrote in message .. .

Someone else said, "Why would you want to go from a smooth running, fuel
sipping six cylinder to a vibrating, fuel gulping four cylinder?"

I agree, especially when you can go to a smooth running, fuel sipping
six cylinder that has 220 hp. The Franklin 220 is STCed for your 172, I
believe. Check out http://franklinengines.com/cessna.cfm

Don't know the cost. I have one friend who installed a Franklin 220 in
his 170A. I think it set him back about $25,000 total.

Good one! I'd forgotten about the Franklin option. I flew one of
these several years ago. Taking off from 7,000 MSL it was climbing
like a 182 at sea level. 10 less horsepower than a 182 with the
airframe weight of a 172. I liked it.

John Galban=====N4BQ (PA28-180)