Boss 338 - 20x8.5 on 1.25 Rotors - No Mods - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**fredm98** · 04-29-2013, 10:19 PM

I got a set of these 20x8.5 Boss 338 with the full expectations of machining down the rotor. But to my wonderful surprise, they bolted right on, no spacers, no grinding, no turning down, perfect fit. These are the style with the O-ring cap. The rotors are off a 1976 1/2 ton. 255-40-20 front and 285-40-20 rear on 20x8.5 wheels all the way around.

**fredm98** · 04-29-2013, 10:21 PM

more pics

bugmasta · 04-29-2013, 10:22 PM

Sweet! My wheels will be here tomorrow so I am hoping for the same luck. I am fully prepared to grind but if I don't have to, AWESOME!

fingers crossed........
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fastnotch89 · 04-30-2013, 05:22 PM

The 20's with stock rotors and spindles you will need a spacer, on the 22's like i have, all i had to do is knock the dush cover in just alittle.

bugmasta · 04-30-2013, 10:58 PM

Wheels came and I had to grind down the rotors. No big deal. I have factory 72 rotors on the front so not surprised. Tires show up tomorrow so new shoes will be rolling tomorrow afternoon.
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ulakovic22 · 05-01-2013, 10:23 AM

Good looking truck, what are the specs on the drop?

Codez67Chevy · 05-01-2013, 12:12 PM

Nice Mitutoyo's lol and wheels.
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**fredm98** · 05-02-2013, 07:59 PM

Quote:

Originally Posted by ulakovic22

Good looking truck, what are the specs on the drop?

Well I'd estimate it a 4-6 maybe 4.5-6.5? I cut a half turn from the springs and have 2-1/2 drop spindles. The rear springs are junkyard find out of a late model full size chevy car. How do you calculate the drop? Maybe measure from the centerline of the wheel to the top of the wheel arch? What are those measurements from the factory?

**fredm98** · 05-02-2013, 08:01 PM

Quote:

Originally Posted by bugmasta

Wheels came and I had to grind down the rotors. No big deal. I have factory 72 rotors on the front so not surprised. Tires show up tomorrow so new shoes will be rolling tomorrow afternoon.
Posted via Mobile Device

bummer you had to grind. Must be the 73-79 rotors are thinner. Post up some pics once you get her all rollin'

bugmasta · 05-03-2013, 08:56 AM

Quote:

Originally Posted by fredm98

bummer you had to grind. Must be the 73-79 rotors are thinner. Post up some pics once you get her all rollin'

up and rollin! had to add 1.25 spacers to the rear as well even with a 72 rearend.

04-29-2013, 10:19 PM	#1
fredm98 Active Member Join Date: May 2009 Location: Sioux Falls, SD Posts: 110	Boss 338 - 20x8.5 on 1.25 Rotors - No Mods I got a set of these 20x8.5 Boss 338 with the full expectations of machining down the rotor. But to my wonderful surprise, they bolted right on, no spacers, no grinding, no turning down, perfect fit. These are the style with the O-ring cap. The rotors are off a 1976 1/2 ton. 255-40-20 front and 285-40-20 rear on 20x8.5 wheels all the way around. Attached Images

04-29-2013, 10:21 PM	#2
fredm98 Active Member Join Date: May 2009 Location: Sioux Falls, SD Posts: 110	Re: Boss 338 - 20x8.5 on 1.25 Rotors - No Mods more pics Attached Images

04-29-2013, 10:22 PM	#3
bugmasta Registered User Join Date: Aug 2009 Location: North Bend, WA Posts: 272	Re: Boss 338 - 20x8.5 on 1.25 Rotors - No Mods Sweet! My wheels will be here tomorrow so I am hoping for the same luck. I am fully prepared to grind but if I don't have to, AWESOME! fingers crossed........ Posted via Mobile Device __________________ 68 c20 build: http://67-72chevytrucks.com/vboard/s...d.php?t=358130 Club longbed ...cause girls like'em long!!!!!

04-30-2013, 05:22 PM	#4
fastnotch89 Registered User Join Date: Apr 2013 Location: Clover,SC Posts: 142	Re: Boss 338 - 20x8.5 on 1.25 Rotors - No Mods The 20's with stock rotors and spindles you will need a spacer, on the 22's like i have, all i had to do is knock the dush cover in just alittle.

04-30-2013, 10:58 PM	#5
bugmasta Registered User Join Date: Aug 2009 Location: North Bend, WA Posts: 272	Re: Boss 338 - 20x8.5 on 1.25 Rotors - No Mods Wheels came and I had to grind down the rotors. No big deal. I have factory 72 rotors on the front so not surprised. Tires show up tomorrow so new shoes will be rolling tomorrow afternoon. Posted via Mobile Device __________________ 68 c20 build: http://67-72chevytrucks.com/vboard/s...d.php?t=358130 Club longbed ...cause girls like'em long!!!!!

05-01-2013, 10:23 AM	#6
ulakovic22 Registered User Join Date: Aug 2008 Location: Lantana, TX Posts: 419	Re: Boss 338 - 20x8.5 on 1.25 Rotors - No Mods Good looking truck, what are the specs on the drop?

05-01-2013, 12:12 PM	#7
Codez67Chevy Registered User Join Date: Nov 2012 Location: Spanish Fork Ut Posts: 370	Re: Boss 338 - 20x8.5 on 1.25 Rotors - No Mods Nice Mitutoyo's lol and wheels. Posted via Mobile Device __________________ " Dead Pumpkin" 67 Chevy short bed, 292 I6, 4spd manual. Fan of the "Slant Noses". 93' Toyota pickup 2WD 2dr and 32mpg. Daily driver. 300k+ Members I've met... Mister-B

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