Check out AJ Sims site. A lot of good info on Kads there
http://www.lowbugget.com/
Are they any good??
It all depends.
They can run rich and cause run on.
They wont breath as much as twin 2 barrel Webers or Dellortos and probabally harder to get jets for.
They will run out of breath if you go much bigger than the 1776 and not as manipuable (??) as the twin 2 bbls.
I think all agree there stock linkage sucks. Plastic clips pop off real easy
The aluminium manifold is better that the old steel ones.
If you look hard enough you can get old single port manifolds for them.
They are cheap/more affordable than Weber ICT's and Dell FRD's (twin single bbl's) and a lot cheaper than Weber IDF's or IDA's and Dell DRLA's (twin dual bbl's)
If you have them then they are good.
Work with what you have.
Or sell them and get a set of Dual 2 bbls