I would use the SU HS6 carbs. They are easy to set up and there is a much better selection of metering needles to chose from if/when you decide to modify the motor. The HIF6's were designed more for emission control and are not as flexible to use. I never did like the bimetal strip that holds the main jet in place. The idle and fuel mixture tended to flucuate with the temp changes. However, one can saw off the two metal strips that sandwhich the jet holder and then you have a single metal strip which is more stable.

If your motor is basicly stock KD needles work great. Just my .02$ worth.

Jim