Carburetor pricing

[lucaspa]

I am new to building bikes and am looking for a set of carbs for a cb750k DOHC 1980. This is posted on craigslist but I wanted to get some thoughts on prices , etc before making a purchase. http://portland.craigslist.org/clk/mcy/3670001193.html

What is a common price for a set of complete old carbs not rebuilt?
Are keihin Vb42b the OEM carb for my model bike?
Other than inlet diameter and jetting what determines what carbs my DOHC can use?

I really appreciate the help. I am rebuilding this engine (1st one) complete ovehaul, and would like to be able to fire her up when done. I will be starting a project post soon as well. Thanks in advance for the help.

 

[davidgwells]

The ones in the ad are for a sohc cb, not a dohc like yours.

 

[lucaspa]

Thanks for the info, what gave it away the size, shape or something entirely different? I have a basic knowledge of carbs and would think with some re-jetting and fitting a sohc carb could be made to run a dohc although this may be stretching it if there is a significant diameter or pathway change. or if one carb is constant vac vs the other not being so. This is of course theoretical and may not be worth it in real life ( money, time, hassle). I am new to this so will not be attempting to do this and will stick to trying to find a set that will work for my engine but was just wondering if this has been done by anyone on this site?