Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5
 

haha gotta love the kenuter valve/flux capacitor setup. been using that one for years!

Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5
 

Would these wheels fit a large GM car rotor that has 5x5 (what was that, Caprice or Roadmaster?) And if so, will the car rotor work on our truck with a bearing change?

Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5
 

Did a quick search Rock Auto for this idea. They list the same Raybestos part number for the rotors for the 1978-1990 Caprice (along with some Buick and Cadillac models) and the 1981-1987 Chevy/GMC 1/2 ton pickups. Same issue with the 71-72 C10 and the 71-76 Caprice and Caprice Classic.

So, this looks like this would not work any better...

Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5
 

I'm sorry..... I don't recall saying anything about melting ;) . My logic was more on the heat cycles, bearing grease, & road grime that's typically associated w/the spindle hub area.

These are nice looking wheels. Not nice enough to jump through the hoops required to run them w/1/2 ton truck rotors IMO.

Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5
 

can you advise how much was machined from the rotor snout.

Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5
 

Anyone have an idea of which car/application/front rotor this is suppose to fit w/o modifications?

Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5
 

Methinks I might just stick with the Coys C-5s

Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5
 

That's a good question.
Maybe these were designed for the 88-98 2wd trucks?

Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5
 

ScotI dont take things so seriously, My point being you have little choice in the matter if you insist on running this wheel ( i am already committed), I feel you probably stand the same chance in loosing the cap while siliconed on as you do with the weak clips they come with.

Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5
 

Haha, this is a good thread. :lol: Thanks for all the pics and info on these. It looks like you've helped us all on these. I'm curious too, what are these wheels designed for? They do look good, just is it worth saving a few bucks to go through all this, or just get some coys with a little less problems?

Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5
 

Jbham88 I simply machined them until they fit taking care to keep as much material as possible around the race ares , This is why I suggest the coning. I can tell you the end of the snout was machined down to the same size as the aftermarket replacement cap and it only has about 1/32 of an inch clearance in the wheel.

Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5
 

They Have to fit something I dont have a local dealer to find out

Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5
 

Damn these are beautiful wheels,nice choice.

Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5
 

Neither should you. I edited my response to better portray the mindset.

Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5
 

it seems like quite an amount of work to get these wheels to fit but at the end you will be unique...

Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5
 

Mod to dust cap

Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5
 

Just about there

Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5
 

That's a sweet burb BTW.

Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5
 

Thanks SCOTI !

Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5
 

it looks killer,worth the work rob:metal:

Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5
 

I found a retailer on the web that had this info posted. I just Googled "BOSS 338 fitment guide" and chose one. Although these are 18" I think we determined that the hub area is the same on the 18 and the 20". I just cut and pasted the info below. Notice that the vehicle that I chose was a 71 Blazer, It didnt give a 5 lug 71 truck as an option. These have "gauranteed fitment" I guess that no one has tried it on a truck rotor tho. It does have the other models listed that these are suppose to fit in a 5x5 lug pattern. Any of these GM rotors interchange with our trucks?
OEM tires: 225/75-15 (717x225mm). Bolt pattern: 5x127 (5x5). Offset: -10 to 10 mm. Tires up to 757x265mm. Rims up to 23x9.5".
Browse:
What Fits

Styles
Specs

TIRES
DIRECT FIT package. [ Fitment Guarantee] See package options See what else fits
Back
BOSS 338 B
18x9.5, Bolt Pattern (PCD) 5x127 (5x5), Offset (ET) -4mm
Gray/Machined Lip, $169.00 each.
5x127 (5x5) bolt pattern, offset -4 is considerable for:
( 18x9.5 size can be unsuitable for certain models/years/trims )
Buick: Roadmaster
Cadillac: DeVille
Chevrolet: 1500 2WD truck Astro Blazer 2WD C10 C1500 454SS truck Impala Laredo 2WD Suburban 1500 2WD Tahoe 2WD Van 5 lug
GMC: 1500 2WD truck Jimmy Full Size 2WD Safari Savana 1500 Suburban 1500 2WD
Lincoln: Continental Mark III

I also looked for Astro van rotors for a pic-notice the step in the hub that is similar to the machined version that was modified for the 'burb

Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5
 

are these the same wheels?

Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5
 

I think so Al.

Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5
 

I think that I know whats going on here with the rotors. After 1988 all 5x5 rotors are 'stepped' on the hub like the Astro van rotors that I posted the pics above. i just looked up 88 & up applications for C/10, Van, burb and so on and all are stepped. prior years are not.
So the kwestion (my kue doesnt work on my keyboard) is there a way to run the later model rotors (88 & later) (ed:I have since found out there isnt)
I am running an 1986 crossmember with 2 1/2" drop spindles.

BTW, The coys dont fit w/o mods either. Here is a thread for reading with good photos on the coys. The 71-87 rotor hubs are the problem...after 88 I beleive the BOSS 338 or the Coys just bolt on w/o any mods
http://67-72chevytrucks.com/vboard/s...d.php?t=300737

UPDATE-I went to AutoZone and asked them to put an 86 rotor and a 88 rotor on the bench so that I could compare them- the 88 and later hub (and thus the spindle) is 1" shorter than the 87 & earlier stuff. That explains how the BOSS center cap clips in as designed. There would be ample room on the 88 and up rotor.
here is a 1988 & up rotor

The only other thing to check is if 88 & up spindles (with these smaller rotors & brake components)
would work on 67-72 suspensions.....if not, the grinding/lathe turning proceedure will be the only way to run these wheels.
Maybe useless info, but it doesnt cost anything to gather......and maybe help someone else

Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5
 

I'm not poking fun here, but for some reason I couldn't stop laughing, not because your 'kue' doesn't work, but because you just kept on truckin' without it! that's awesome!