Sorry, just raising the compression won't increase the horsepower nearly that much by itself. I did a little fiddling around with Dyno2000 and just raising the compression (while keeping everything else stock) showed a 19 hp gain.
The addition of a 600 CFM 4-barrel and headers with mufflers added another 30 hp.
A mild cam added another 30 or so.
These are just computer simulation numbers, so I wouldn't put any real faith into them, but they can be useful to see that it takes more than just one single item to generate power.
Another thing to consider is the 160 hp is "Gross" and what you measure on a dyno will depend on how it's done. If it's a chassis dyno, you'll see rear wheel hp which can be significantly lower than flywheel hp. Testing it with and without engine accessories (alternator, power steering pump, A/C compressor, etc.) can have a dramatic effect on "Net" hp.
I've been building motors and hot rods for a while and I've never heard of anyone comparing mileage between max compression for high octane fuel vs max compression for regular gas. Maybe because mileage is such a subjective thing. One thing ic constant: you'll pay more for premium gas. And in my opinion, raising the compression won't do enough for mileage to make it cost-effective from a mileage standpoint. If you want lots of power, then higher compression is great.
Bottom line: a motor's (or a vehicle's) power and driveability are the result of many different factors. And what's good for me might not be right for the next fella as far as driveability. Along those lines, I wouldn't want a motor that made a whole buncha horsepower at 7000 rpm and very little torque at 2000 unless I was gonna be using it solely for racing. Conversely, a motor that makes moderate power at 4000 rpm and has a flat torque curve from 1500 to 4000 might feel a whole lot stronger that the race motor when driven on the street.
The best advice I've been given is to determine what I want as far as the purpose of the vehicle and then combine the appropriate parts to come as close to the goal as you can without any major negative trade-offs.
Good luck with it.
