High compression pistons will increase your power output but also increase the tendency for pre-ignition (spark knock). There can also be problems with valve to piston clearance if running an extremely high lift cam.
Stroker engines do usually have increased compression. They give you more torque due to the mechanical advantage they provide as well as the increase in displacement. They can and I'm gonna say often do vibrate more than the stock stroke.

 

I kind of did both. My cases were factory 1979, so I don't like to punch them out and just left the factory case bore.

The jugs are set up for a 3.5" piston.

I went with S&S HC pistons (for a 4 5/8 stroke) but I have a 4.5" stroke. I then trimmed the jugs to split the difference. What I ended up with was around 10:1 with a 4.5 stroke. Nothing crazy in my opinion. It's got plenty of power, and doesn't knock with 91 octane.

 

All things equal, a higher compression ratio increases torque only. Increasing displacement with a longer stroke will increase both torque and HP. An advantage that I like with a longer stroke is a smaller piston dome which improves the burn in the chamber. In the case of a harley it makes a terrible design a little less crappy.

 

High compression means more heat. Are you (and your 46 year old motorcycle) ready to deal with more heat?

I have a riding buddy who has A LOT of bikes. He only rides his older stuff during fall/winter/spring months, to reduce stress on old running gear. Something to think about...

 

Whats considered high and what cam is being used? Im running 9:1 which is high compared to stock but Im not running a stock cam. The intake valve closing time determines dynamic compression ratio (usable compression ratio) which effects torque and heat. I could have a similar dynamic compression ratio to stock with my 9:1 pistons and an appropriate cam so heat generation would be a moot point.

 

All things being equal ( almost ) my stroked shovel doesn't seem to throw off any more heat than my twin cam ...

 

just like with woman more inches is better -

on another note todays gas has me in my shop doing things unthinkable years back - like I favor no more then 8 1/2 but increase the duration with that as well, the best combo we do is the 89 its the cats *** - knuckle - pan - shovel and the evo all love the 4 - 5/8 stroke - 74 = 86 or 80 = 89 inch both are just fine with 8 or 8 1/2 to one = and will run 75 thousand miles between overhauls - all bets are off if your an idiot

 

As said... no Substitute for Cubic Inches... especially when torque or Rideability is desired... now Horsepower... Horsepower is a Product of RPM [look at how it is measured] We call it "pops per quarter mile" certainly Not a product of longer stroke.. All of this assumes you know exactly what you intend to accomplish. Drag Racing??? short stroke/big bore spin it hard= Win!!! Fun to ride = Stroker... downside being more stroke equals more vibration, and harder on driveline parts [assuming you actually use it]. A simple compression increase... within reason [no spark knock] along with the correct cam... = good , cheap. Fun!! Downside=No Braggging.
Choose yer poison... only Jap Bike guys Brag about Horsepower!!!! For good reason!!!!

 

as we know I run 11:1 compression - it has a L-3 cam - dual plugs -- the squish is set at .003 - I can run 87 octane and no knock -- in the heat down here I replaced the stock oil cooler and added a bigger one and it has a electric fan with a probe that goes in the oil -- I set it for 190 and the fan comes on.. it only comes on in traffic but im glad I have it (have to take a pic) -- mine is big bore short stroke - I like the zippy out the hole through the gears -- not really interested in top end -- I have a J-2 and a L-5 if I want that -- I also have 2 old sifton cams a 468S and a 468+ -- I wanna try the 468S but right now it runs to good --