I took a long nap today so I can ramble here a bit.
Seriously, I've just done one this summer and I learned the "hard way" what I'll do next time. This advice is free -
1) The Wiseco 836cc kit is kick-a$$. Forged pistons, new pins, special head hasket for the big bore and replacement rings only $75 a set - Sweet.
2) Megacams makes a 375 lift cam with 256 degrees of duration at .40 made just for the 836 # 12565 - Sweet.
3) Absolutely have your heads ported. Mike does pretty work, but whomever does it - have it done.
4) Brass valve guides - Dynoman has them - Sweet.
5) Stainless valves - Dynoman has them - Sweet.
6) Titanium retainers - again, Dynoman has them.
7) Performance dual valve springs - Dynoman has these too.
New, stock clutch fibers and steels (ain't cheap, but produce the smoothest shifts) and with Barnett's springs will hold like a Mack truck.
9) Rods - Good Rods and bolts. This is where I messed up. Horsepower is a mathematical result derived from pounds/feet torque x rpm divided by 5252. With all this 836cc, 10.25:1 compression, ported heads, titanium retainers, performance springs and other goodies, there is still a finite amount of torque available. Rpm is the only way to "raise the bar" - horsepower bar that is. With stock rods and those newly installed Wiseco forged pistons at 836cc - the stock K0~K6 is only safe to 8,500. This is the 1 single thing I wish I'd done - added the Carillo rods and bolts. Once you get them built like described above, they will turn. With performance rods I'd spin this thing to 11,000 if she'd pull it.
10) Dyna 2000 with a built-in rev limiter is going to be very desirable. In less than 200 miles I found myself missing a few shifts and blistering the clutch, so mine saw the 10 + mark more than it should have. Problem solved - Dyna was installed this week.
Ok, I've rambled. But seriously, if you want to impress your friends, out run any stock H2 Kawasaki out there, and smile at every light - this old CB is a great, cheap way to do it. It's the perfect sleeper. Mods are going to run $3000 is my estimate plus exhaust, dyna, and filters. For $1,100 more you can add insurance and 3,000 rpm to the mix. If 80% of the torque is maintained, that's worth 20 extra horsepower - $55 each, not bad.