On the LD340, I'd just tune the 600 DP. A slightly larger carb falls in your lap, then its worth experimenting.
Running an LD340 on the current 340 and in the lower rpm ranges I think it looses velocity in the runners.
I've had an RPM sitting on the shelf for a few years now but haven't had an opportunity to swap them.
IMO decent headers and exhaust will help keep things flowing into the cylinders.
A larger carb may pay off at the track if you're looking for more top end in the 1/4 mile.
Should add my current 340 has a Hughes cam in the same range as that Lunati. something like 223/230 505/515 or so
Not sure I'd use air gap version in Canada. All depends on how you use the car and what sort of fuel your running.
