I think a lot of turnkey's are set up at 8 1/2:1 because it's a good mid-point; it's about right for a W110 (247' @.050" dur), which is a pretty popular cam. If you spec a W100 (236' @.050") it's not too hard to get the compression down to 8 1/4 or 8:1 and if you go the other way to a W120 (253') or W125 (262'), again, it's usually not too hard to get it up to 9 or 9 1/2.
An 82mm crankshaft coupled with 92mm pistons and cylinders is 2180cc's; to go bigger (which I think you should do so you're not reaching your target power at such a high rpm point) you'll have to either increase the stroke or the piston size (or both! ). 84x92 is 2234cc's and 86x92= 2287. These crankshafts are harder to fit, so expect to pay more for someone else building it. Again, cut a hole in the firewall (you could even duct air into the hole from a scoop attached to the torsion bar housing) and you'll have no problem running 94's- 82x94=2276, 84x94=2332 and 86x94 is almost 2400cc's (2386). Displacement is your friend here; 180hp in a 2 liter or 2110 happens around the 6500-7000 mark; the same hp in an engine 2-300cc's bigger happens 500-1,000 rpm lower, with a much more street-
In my earlier post with the engine combo recommendation I suggested the FK8 (with 1.4 rockers) because it will allow the rpm and have the valve lift to make the power you're looking for, but still be docile enough to drive everyday (or every nice day), jump into it for a weekend trip at a moment's notice and not require a lot of maintenance. The CB2295 has 270' @.050" (I keep on quoting the dur @0.050" figures because they are more indicative of a cam's potential; some aftermarket VW cams have as much as 50' or as little as 25' difference between the advertised and @. 050" duration figures) which means it has the ability to go with power to well over 7,000rpm (as long as the rest of the engine is right) and if you use that a fair bit (and who wouldn't!), valve springs won't last as long, the heads will need to come off for maintenance more often and the beginning of the powerband will be moved up enough that the engine will be more of a "Saturday night bullet" than a fast, go anywhere cruiser. Also, to get enough valve lift (.530-.550") to make the heads live up to anywhere near their potential, the engine will need at least 1.25 rockers with the 2295. The use of higher ratio rocker than specced will add a few more degrees to the dur @.050" number as well, and at 273-275' @.050' this is now a 7500rpm watch winder. It would be easier on parts to use a cam designed for 1.4 rockers so there's less lift at the cam and the rockers provide more of the final valve lift. You'll be able to run 10- 10 1/2:1 with this combo, but now you'll have created a 200-210hp monster that doesn't like the highway at all.
Again, talk to Pat about your head and valve size choice (as well as all the components);you want to make sure that the head(s) will deliver the power you're looking for on the engine you want to build. Don't worry about intake ports being highly polished; it's been that a slightly textured surface is better for fuel/air atomization and power. VW's are a little different than V8's in that most cams are ground on107- 108 lobe centers for a pretty good balance of lower and upper end power.
I guess my point is to watch out what you wish for. The couple guys I know with really fast bugs (one is a '67, 2442 with 86C cam and is scary fast) don't actually drive them all that much. You'll get much more enjoyment out of something just a little more "tame"
Hope this helps. Al
PS- Don't get me wrong; if what you want is something that's faster than almost everything on the road, great. I just want you to know what it entails. And 160 or 180hp in a 17-1800lb. car is WICKEDLY FAST!!!
And keep in touch; I want to know what you build and how it turns out.