In the early days of the CB 750, American Turbo Pak (ATP) had a Turbo kit for the 750 which was sold as sort of bolt on horsepower.
That kit consisted of a Rayjay turbo, a Zenith or Mikuni carburetor, and the necessary headers and manifolds. Unfortunately, turbocharging an engine is not as easy as bolting on some equipment and doubling your horsepower, a lession which was learned quickly. (ATP has gone out of business, by the way)
I was able to get hold of an almost complete ATP kit:
A turbo engine should have a low base compression ratio, a mild cam with little overlap and a strong bottom end able to handle the additional power.
Also, the ignition should be retardable - with increasing boost the engine tends to detonation. That can be fought by retarding the ignition and/or injecting water.
My current plans are as follows: A '78 engine case, an automatic crank and hy-vlo primary chain, Falicon or Carillo rods, reinforced cylinder studs. A 67mm/888cc cylinder barrel with cast pistons, along with a '78 F cylinder head. The combination of the late F2 head with an early big bore kit should come out with a compression ratio of about 8:1.
Then use VEMS (a do-it-yourself engine controller) or a similar microcontroller based ignition to control the ignition and probably water injection, based on boost pressure and engine speed.
Oh yes, and a BIG oil cooler!
This is still in a planning state - I keep on collecting the necessary parts, but it is making progress. Watch this space!