Just a quick drop-in...
I'm on Twin 45's, though the car is plumbed for injection should the need arrise.
I don't get spitting of the carbs on either of the Zetec's nor the CVH before. So I'm with the others, it's a set-up issue, they should be silky smooth.
As for emissions, I know that both the CVH and the race engine were/are very efficient units and from recollection the emissions were surprisingly low... There were comments made at the time.
As an 85 car whilst it's road registered the emissions regs are only visual check. I thought you were ok if it was pre 92?! - but don't take that as gospel... Need to do some proper checking.
As for bike carbs... I've seen a few set-ups, but the manifolds always look a bit basic and the set-up can be more hard work than seemingly necessary but they are cheaper.
A decent setup should be all that's needed....
In terms of weekend racing.... Look out for the update coming soon!!! With pics.....