I came across this video about some of the complexities of exhaust systems on bikes. It's very simple and concise and it probably won't be very informative to the old-timers here. But Newbies (like me) might find it useful. It discusses back pressure, noise, performance etc. The example is for a modern sports bike, but the basic concepts are still applicable.

https://www.youtube.com/watch?v=3QCIIDSYJLc

A couple of points caught my attention:

1. The exhaust in the demo has a back-pressure valve. I assume we get our back pressure from the muffler itself. So no baffle = no back pressure?

2. the example here is for bikes with EFI but the basic concept of tuning for the exhaust still applies.

Aaaaaand, it looks great on the Savage 😎

The higher compress piston is the biggest boost in power ,it's the cake, consider a higher performance cam as the icing . You'll have to determine how much performance you want and balance that against reliability /cost.
  The 94mm piston from Lancer shouldn't require boring of the cylinder, ( you should use a ridge reamer -the piston sets higher in the bore, and you should hone the cylinder wall) a mild cam could be a Webcam standard, I think Armen uses that one ,and I would too. '
     the Savage rocker arm ratios are intake-1.3   exhaust-1.352   stock  cam lobes .254/.244  =    .330 /.330  -.005 valve clearance  .325/325
     WEBCAM lobes .256/.256 = .333/.346 - .005 -.328/.341
It gives higher lift mostly to the exhaust valve  keeping it farther out of the exhaust path and the cam has slightly longer duration, just what the doctor ordered.  It should allow you to use the Dyna muffler and the CV carb , you could always go to a 36mm VM later if you choose to. Tuning your intake is also a way of boosting hp and torque.

10% more hp is a bit high, it's more like 5.5% if you raise compression from 8.5 to 9.5  that maybe all you'll get from the savage but that isn't counting  the cam.     If you tried to get to 10.5 compression you'd get only 7.7% more hp   (It's like getting 15 people in a VW bug the next 2 gets much harder )

the piston is a good move ,the higher compression will show gains in hp/torque throughout your entire rpm range < but you have to remove the top end to replace the piston, so adding the cam makes sense, and neither of these upgrades will affect your reliability.. webcam designed the cam for use in the savage ,the dr650 cam is cheaper , but I feel it doesn't address the  poor performance of our exhaust channel as well.The DR has equally as good intake and exhaust channels in the head allowing similar balanced cam lobe lifts , the Savage has a bad exhaust channel ,the web cam deals with this by keeping the intake lobe only slightly higher (to make up for the room the valve stem takes up at the port ) and greatly increases the lift and a bit more duration(2 degrees) to allow more time to remove spent gases .