If you want some more info on flowing more air through this carb see if you can get a copy of "Tuning BL's A-series engine" by David Vizard. This is a Haynes book ISBN 0-85429-732-4 or Library of Congress catalog card no. 88-82693. Very comprehensive chapter on this subject.
TimC

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

Depends on where you are. In the east it is Joe Curto in New York,(718)762-7878
and in the west it is Rhys at Island Automotion, (250)479-5482
Either one can and will discuss your problem and help you obtain the best
solution.

If I were you I would forget "tweaking" until you get them on and running
right. They are big enough that the butterfly screws only add a little
desirable turbulence for better mixing, in my opinion. And if you take off
the split ends, you run the chance of loosening or losing them down the throat.

Things you should pay attention to: Dashpots, float valves and especially
throttle shaft seals. Of course the bottom plate seal is also important.
--
George Downs Bartlesville, Heart of the USA!

Burlen Fuel Systems in the UK has rebuild kits; they are the owners of the SU name. Site is here: I know they send what you ask for.
--
Stef -- 1981 245 B21A SU M46 323000km my volvo pages