I can't imagine a more nightmarish thought than trying to tune this set up. With 4 carbs to tune individually, 2 engine mechanical and ignition timings to deal with, not to mention the possibility of the 2 center intakes very real likelihood of ingesting lessened intake charges just due to their proximity, it would be enough to make most tuners ...

No 2 engines, even with identical builds, will output in exactly the same way, meaning there are 2 different HP outputs to be dealt with ongoingly in this set up.

If they'd have used fuel injection instead of carburetors, they'd have at least added in a level of consistency that would have made the overall package more manageable/tuneable with the help of electronic engine management ... and don't even get me started on their use of blowers!

Just a guess, but I'd say it's likely there's at least a thousand HPlost in this set up due to hardware choices, required tuning compromises and drivetrain losses.

Is this set up pretty, neat to look at and cost buttloads of cash to build and maintain .... oh hell yeah. My guess though is for the same $$ they could problee have built their own custom designed single 1000 CID engine, used injection, turbos and electronic engine management, which would have been equally cool to look at, yet be ultimately much easier to maintain/tune, while outputting at least 2X the HP this set up does, hell, there are single 300 CID twin turbo V-8s that put out 1500 HP!

'Course then they'd have needed to contact NASA to try and get 'em to design a tranny for it