Soliciting thoughts & opinions - power upgrades to a 998

[MPlayle]

As the title implies, I am looking for thoughts/opinions on methods for getting a bit more power out of my 998 engine.  I find running with highway traffic at 4K rpm for much time is tiring on me, though necessary for getting in/out of San Antonio.  There are also a few hills that Bruce and I go over on our drives to area C&C events where I still lose significant momentum on the uphill.

The engine currently runs very nicely: has good oil pressure, does not overheat, gets me 30 - 33 mpg regularly.  The transmission/differential is currently set up such that 4K rpm is 70 mph (3.1 final drive, but non-standard drop gears make it act like a 3.2 final drive)

The engine spec as it is currently: stock pistons and cam; alloy intake manifold supporting a single HS-4 carb with a K&N filter in a modified stock air box; LCB exhaust; Mini Sport "Stage-3" 998 head with mild porting and bigger valves; forged 1.4:1 ratio rocker arm set.  The head and rockers were done to boost the power slightly from stock when I changed the final drive to the current setup.

What I would like to do is add more power so I can change the final drive again to either a 2.95 or 2.76 to lower the rpm more when doing highway speeds while still having sufficient power/torque for the winding hill country backroads.

The approaches I know of are: 1) upgrade to a 1275 based engine; 2) overbore and change the cam in the current 998; or 3) add a turbo kit to the existing spec.

Please chime in with your thoughts, pros/cons of the above approaches, any other alternative approaches.

[MiniDave]

1275 motor/gearbox would be my first choice because it's all bolt in. Turbo to the existing engine would be second choice because kits exist that again are (supposedly) bolt on stuff, but spendy ($5K+).

I run a 2:76 in my green Mini, 70 mph is about 3300 rpm, 75-80 is 34-3600 rpm. I only have to downshift to 3rd if it's a really steep hill or if I'm at altitude (Colorado Mtns)

I like turbo motors in general, don't know what to expect from the Jet motors kit on a 998, but the mods you've already done will help quite a bit, I would call Jeremy and see what he says.