Don't forget that if you install the 73up brakes ( A great idea IMO), your front track will increase about 3/8" per side, putting your tires that much closer to the fender line. That system already comes with a 4.5 Bolt circle.
But here's the thing;
if you already have a set of front wheels that you like, and they happen to be small bolt circle, IMO, I would just use the KH 4-piston system. They are more than adequate on the street with street tires. And according to the FABO chatter on here, they are better than some of the junk engineered systems out there.
And BTW; Having driven on GoodYear Polyglass E70-14s back in the day, IMO;
IMO those were the junkiest tires ever.
But they were, in 1970, about the best TYPE of tire ever put on a Mopar, to that date. They were however woefully inadequately sized for any 340 equipped,Mopar A-body. But, you could do tricks with them . Tricks like changing lanes by flicking the steering wheel, and skating sideways. Like doing 360s anywhere anytime, by flicking too far and too hard. Like laying endless blackies. Like painting the hiways with all kinds of interesting patterns. Like banging shopping carts across the Safeway lots, doing 360s wit the rear tires on fire. And like accident avoidance maneuvers that actually caused other accidents; which is how in grade 10, I got the nicknames of "ditcher" and "ditch-hitter." That 70 Dart on those crap tires was a plow, a pendulum, a rollerskate and a real handful to drive, on those tires; as anyone who ever had one can attest to.
That all changed when radials came out, in 73 I think it was. And I went and got me a set rightaway, couldn't get rid of those stockers fast enough. And wider wheels too. I joined the big and little crowd, like the AAR Cudas.
