8R19.5 Tires - its really not a Chevy thread.

[NTOLERANCE]

Saw something today that kinda piqued my interest.

Typical 80's Chevy Dually, with a flat bed. First thing I noticed was big detroit diesel stickers on the hood....

nope, sorry, it was a 6.2. Then I noticed how high the truck was setting, and man those 6 tires are skinny.

Yep, 8R19.5. 8 lug dually rims, and tires.

Wish I could have taken a pic, but I was at a customer and its frowned upon there.

I think the truck had a turbo 400, so I would assume the really tall tires dropped the rpm alot.

Anyone else run tires that big?


Are there rims available some place?

 

[NTOLERANCE]

Now that I think about it, they may have been GM P30 rims?

 

[gonecrazyi]

There's a few early 80s Chevy CC dually 4x4s running around here with those rims and tires looks decent but nit wide enough lol.

 

[rjjp]

That's only what, 33"?
I still want 9.00R16 (just over 36").

 

[Dave 001]

Now that I think about it, they may have been GM P30 rims?

Chevy did make some P30 chassis' with 19.5" rims/tires. I know they had 14 bolt rears......so a 14 bolt rear factory setup from a P30 with 19.5 rims/tires may very well built right into a one ton truck. The front rotors and brakes my bolt right up too. Might be an easy swap.

 

[LCAM-01XA]

Now that I think about it, they may have been GM P30 rims?

Probably, IIRC them P30 wheels are direct bolt-on for chevy dually trucks that came w/ 16s or even 16.5s from the factory, and 19.5" commercial tires make for much more stable ride especially around corners w/ top-heavy loads. I've seen them on Ford trucks as well, but they need some machine work first, the hub pilot hole needs opened up from 4.56" to 4.88" or it won't slip over the hubs.

That's only what, 33"?
I still want 9.00R16 (just over 36").

Ah come on, go all out - 11R16s! lol

Chevy did make some P30 chassis' with 19.5" rims/tires. I know they had 14 bolt rears......so a 14 bolt rear factory setup from a P30 with 19.5 rims/tires may very well built right into a one ton truck. The front rotors and brakes my bolt right up too. Might be an easy swap.

Most Frito Lay delivery trucks I've seen had them, also some larger cutaway cube vans w/ the G-series cab. No need to touch rotors or hubs or anything on the 1-ton truck AFAIK, just bolt wheels on and go, that is assuming tires will clear fenders and such (not always the case w/ 2wd trucks).

 

[92F350CC]

My Class A motorhome is built on a P30 chassis, and it has 19.5s.

 

[jhnlennon]

3500 HD chebbies had them also. Downside to them is PRICE OF TIRES, very expensive. Ride is harsh too.

Technically the 6.2 is a detroit diesel as it was designed and produced by them(Detroit diesel was a subsidary of GM and was started by GM)

 

[Dieselcrawler]

Drive 19.5 ain't to bad in caps. Pops runs them on his f450 and iirc they were 125 a tire.

 

[jhnlennon]

****** drive tires can be insanely expensive in 19.5...

 

[LCAM-01XA]

My Class A motorhome is built on a P30 chassis, and it has 19.5s.

Are you sure it's actually a P30 chassis? If I ain't mistaken the P30 comes w/ 8-lug wheel setup only, and tis also a bit small for a class-A... There is another chassis that is similar to P30 and also uses 19.5 wheels and tires, but driveline and brakes are much beefier, usually that's what I see RVs built on - if yours has 10-lug wheels this is the chassis it uses, forgot its designation tho.

3500 HD chebbies had them also.

Yes and no - the 3500HD does in fact use 19.5" wheels, but they are not the P30 wheels - P30s are 8 on 6.5" bolt pattern, the 3500HD are actually 10-lug wheels (similar to the F-Superduty setup) but just the rear hubs have all 10 studs while the fronts only have 5 so every other lug hole in the front wheels is unused. Cause of this P30 wheels will fit our trucks (seen it in person) and based on wheel dimensions 3500HD wheels should fit the F-Superduty, however in both cases machining the hub pilot opening is required from 4.56" to 4.88" for 8-lug wheels and from 5.25" to 5.46" for the 10-lug ones.

 

[Puller]

I had two 1991 P-30's with the 19.5's and a 14 bolt rear with 8 x6.5" bolt pattern. I don't know why mine had them as I have a friend that has a few P-30's and his ride on 16" wheels. Same size, GVW and drivetrain. It was odd for sure. Never really thought that much of it until I read this thread.

 

[92F350CC]

I'm pretty sure mine is on a P30 chassis, at least according to the title. It's too far away for me to go look at the wheels though, so I don't know how many lugs it has.

 

[Dave 001]

No need to touch rotors or hubs or anything on the 1-ton truck AFAIK, just bolt wheels on and go,

How ya' gonna' do that? The bolt pattern and hub diameters are different.

 

[LCAM-01XA]

How ya' gonna' do that? The bolt pattern and hub diameters are different.

Different between what and what? Like I said there are two different 19.5" wheels that can be found on bread trucks:

a) one 19.5" wheel has 8 on 6.5" lug pattern which is identical to what older 1-ton dually GM trucks use, hub pilot diameter is also the same 4.56" - if that ain't a direct bolt-on, I dunno what is! Easily identifiable by the four hand holes, it essentially looks just like a normal 1-ton dually wheel only larger. Here is one such wheel on ebay: http://www.ebay.com/itm/170818466160. If you wanna use it on a Ford dually you gotta machine the hub pilot opening from 4.56" up to 4.88".

b) the other 19.5" wheel has 10 on 7-1/4" lug pattern, which in GM vehicles is only used on what are essentially medium-duty applications. This wheel can most commonly be found in 3500HD trucks, but some motorhomes also use it. There are 5 hand holes on this wheel. Here is one such wheel on ebay: http://www.ebay.com/itm/251048758022. The 10 on 7-1/4" lug pattern is used on F-Superduty trucks as well, however those have hub pilot of 5.46" as opposed to the 5.25" hub pilot used on Chevys - as w/ 1-tons, if you wanna upgrade your 16" Ford to 19.5" wheels you will have to machine the hub pilot opening larger.

Does it make sense now?