you said your lugs are just like the securex pic i posted yet your description seems to indicate something a bit different. you mentioned acorn--is there a taper or shank on your lug that penetrates through the washer and past the face of the wheel into the lug bore? is the washer on your lug swaged onto the lug so it cannot be removed or are the washers separate? there is no way you could brake a securex washer. securex lugs have their name and 140ft-lbs stamped right on them. why are you trying to torque your lugs to stock spec? the only reason for such a high torque rating is to overcome the friction of the fixed flange washers of the stock lugs. any lug with a washer that swivels loose or even a tapered seat does not require anything approaching 300ft-lbs to tighten. it almost sounds like the lugs you have are what eagle wheels uses. alcoas use the exact system of a 2nd gen wheel, the washer on the lug clamps the wheel, nothing else touches or penetrates the wheel or lug bore. wheels are hub centric by design. could your wheels be eagle? alcoas are stamped with their name, part #, load rating and some other stuff on the rim lip and can be seen on outer rear wheel as mounted on truck. if they are alcoas they can be further identified (in addition to looking up part #) by measuring the hub bore. gm=4.56". dodge=4.77". ford=4.88". unless either the 4 male coins facing the outer wheel have been ground flat or the area around the lug bore on your alum wheels have been clearanced i do not know how the wheels are seating properly.

 

The acorn nuts and concaved washers (separate pieces) are the old style that I replaced with the 2-piece Securex type AFTER one of the concaved washers broke.

I'll have to measure the bores because I can barely make out any of the stamped lettering or numbers. The stampings I can see are just inside the wheel lip on the rears. The rears aren't clearanced for the coins on the steel wheels. They do have Centramatics between them now if that makes up for anything .

 

ive got a 92 w350. I bought a set of 98 dodge dually rims and tires (235/75/16) from a buddy and drilled them out one size over 5/8 and bolted them right up. they dont shimmy, shake, or do anything crazy. Been running them for a year now

 

I just looked at my dana 70 hubs and i can say for a fact that they are not hub centering. Not with a sixteenth inch air gap between the hub and rim.

 

here is what the rear hub/coined wheel fit looks like on my 90 chassis cab dana 70

 

here is a pic of the rear hub with outer wheel removed for measurement/inspection on dana 80 chassis cab on my 95. notice the machined step. my 90 has similiar dimensional
machined surface (4.758-4.76) but does not have such an obvious step.

 

here is a pic of my w350 front hub/coined wheel fit with obvious large gap due to gm spec (4.554-4.555) front hub and dodge wheel hub bore (4.769).