New?
About 600 to 800 depending on how you wanted them (Gas or alky, billet or stock bowls, etc.)
You'll need a new Packard throttle cable as well. They don't make 41s.

Packard will take a 40mm and machine it out to 41.3mm (that's what he did to mine and a few others here)

If you already have 39PWKs and you like them...and are tuned in, I'd say keep them.
I really didn't pick up any time between the PWKs and the Lectrons. I just like the simplicity and easier to tune nature of them, and...to be honest, mine were damn near new and a guy GAVE them to me....

Yea, my 39PWK's are tuned in perfect. I just think I can squeeze a little more outta this motor. I was thinking about 41PWK's. I know I need to gear it a little higher, to get the total feel of the power. It's 15/39 now, and I'm gonna go up to 16 front. That should be about the threshold of the gearing, for long hillclimbs. Anyways, I just think I need more carb, to get this motor's full potential.

Sorry for getting way off topic.

Fastest pass @ Planet Sand Drags had 39PWKs...keep that in mind.

lets not forget about the other mikuni rounds, which have the bowl plug and utilize the air jet, rather than the stock emultion tube. the bowls on stockkers are just cheaper to make than the aftermarket ones with plugs in them

I just got some 28 pwk's and i love em

Can i get some more info on them Lectrons? do they work well with not ported cylinders?

i'll let you know shortly, but it should be any setup....just bought some 30's today, and gonna learn to tune them. anyone got pointers?