seen std alt used with webbers on crossflow so will work with bike carbs.
as for mounting the carbs above the exhaust you can tell you used to work for tsr.
it's a bloody nasty horrrible botch, the carb throats are very close to the firewall, there isn't room to get a good manifold in there the carbs and a pipe, you choudl dent the bulkhead but then if you drive it hard theer is a massive radiant heat issue when you slow down