This set up works for me. I think this valve is for a refrigerator.

I am new to this discussion so if someone has already suggested this just ignore me. Somewhere, sometime, I read about a guy who used motorcycle carbs on (I think) a Datsun 510. He found that any measurable pressure was too much. His solution was to mount the float bowl off of the end of a Holley carburetor on the firewall just a bit higher than the carbs. He fed the float bowl normally from the fuel pump and piped the now gravity fed fuel to the carbs. I see no reason why the float bowls from the SUs wouldn't serve as well as Holleys.
--
Mr. Shannon DeWolfe -- (I've taken to using Mr. because my name tends to mislead folks on the WWW. I am a 49 year old fat man ;-) -- KD5QBL

the mikuni's look great!
is it really a good replacement for the SU's (i say half joking..)

Pearl;

...that looks like a valve...so when partly closed acts as a restrictive orifice ('scuse my French!), and does drop the pressure...but the pressure drop is a function of flow rate (fuel demand)...so at maximum demand you may encounter partial starvation...it's a fine line...the trick is to decrease the pressure to an acceptable level at low demand/load while not incurring so much pressure drop at high demand to create starvation...if you're OK at both extremes...great...you have success.

Cheers

Yeah, I know. Shoulda said "FPR". My plan is to kinda tinker with it to see what works best throughout the RPM range.

Yeah, but you're adding another variable to the tuning with that thing. You really want consistent fuel pressure regardless of demand.

Think of how much you spent on the carb setup... then spring another $30 for a real FPR. Drop in the bucket, and all that.

Phil,
Do you mean FPR ala 240?

No, FPRs for carbs are different from injection FPRs. Most stores that carry aftermarket parts will have adjustable in-line regulators. Quality varies, but I've had good luck with the ones I've had. For a little bit more you can get a good quality Holley regulator that mounts on a fender.

You'll need something that can regulate down to 2 PSI or less, I believe.