Register or Log In To remove these advertisements. |
|
|
|
Thread Tools | Display Modes |
04-27-2013, 10:03 PM | #1 |
Registered User
Join Date: Mar 2007
Location: San Pedro River, SE Arizona
Posts: 734
|
Need info - replacing 16.5 inch wheels and old style tires.
In the process or renewing a 1970 GMC 3500 (with utility bed and nice Alaskan Camper mounted) and want to go to different wheels/tires.
The factory setup is single rear (not dually) and the original front wheels/tires are 7.50/16.5 and the rear are 12/16.5 (quite wide). The load range on those tires is "D". I would like to go to 16" wheels and have the same size wheels/tires on both front and back, but figure that the original owner had those wider wheels/tires on the rear due to weight of the ute body and camper. The camper weighs about 1500 lbs. and the ute body probably 2X (more?) the weight of a stock pickup bed. That rear weight is probably about the same as the old style pickup bed mounted camper setup. If I were to go with one wheel/tire type, say 8 inch wide wheels with 235/85/16 tires in load range "E", would such provide sufficient load capacity without worry about overload? Or. need I to go to wider wheels and load range "F" tires due to the rear weight? Experienced advice will be appreciated. Also, is there any market for very good used 16.5 wheels of the two sizes noted above? Thanks.
__________________
CCCC 67 Sting Ray Coupe 327 4sp; 68 K10 Suburban 327 4sp; 69 K20 Lifted 383 4sp; 69 C80 Fire Truck 478 V6 5sp/2sp; 69 C20 Longhorn 327 4sp; 70 C30 Wrecker 350 4sp; 70 C30 Flat Bed 350 4sp; 71 C20 LWB 350 4sp; 72 K5 Blazer 350 4sp; 72 C30 Flat Bed Gooseneck Hauler with sleeper 350/TH400; 72 C20 Longhorn 402 4sp; 52 Mack LTL Supercharged Cummins 5sp x 3sp; 01 Dodge 5.9 HO Cummins 6spd; 02 Safari Trek 2430 8.1 Vortec on Workhorse Chassis; 03 Silverado 2500 HD 4wd Duramax/Allison Moved but still in the family 70 C20 Custom Camper 350/TH350; 72 K5 Blazer CST Highlander 350/TH350 Recently sent to new homes 72 C30 MoHome 402 4sp; 72 K5 Blazer Conv 350 4sp; 75 GMC 6000 Aerial 350 w Allison; 72 GMC 3500 Utility 350 4sp; 70 GMC 3500, 350 4sp |
04-28-2013, 01:55 AM | #2 |
Registered User
Join Date: Feb 2008
Location: Fort Sumner, NM
Posts: 299
|
Re: Need info - replacing 16.5 inch wheels and old style tires.
If the rears are 9.75x16.5's there seems to always be someone looking for them. I looked for a long time for mine and bought them here on the board.
|
04-28-2013, 03:15 AM | #3 |
Registered User
Join Date: Aug 2010
Location: Edwards, CA
Posts: 7,503
|
Re: Need info - replacing 16.5 inch wheels and old style tires.
Couple of things to think about here. First is that your truck, best case, has a factory rear axle rating of 6340 lb. So your replacement tires need to have a 3170 capacity at a minmum. There are a number of 16" "E" tires but most are 235 and certainly not a wide tire. Problem is these tend to give poor service loaded (check some RV forums). As when the truck was new wider tires provide a bigger contact patch for better control,braking and stability. The 12-16.5 D tires you now have are rated about the same capacity as a 9.50-16.5 E would be. Went out to check my sole remaing 12-16.5 tire but I cannot find an actual weight number on it. Besides its being held down by a horse feeder full of water for my dogs as a splash pool. Might want to look into your options for 17.5 or 19.5" commercial tires/wheels. Been doing that myself looking into on/off road tires.
But first thing I would do is weigh your truck and know what your loaded, front and rear axle weights are. Would not be a bad idea with and without the camper for a baseline. Alaskans tend to run a little heavy and I'm guessing you have a 10' on a utility bed. Even a non-overhead is probably close to 1750 lb wet plus the extras and the service bed. Here are some pages for a 72 C30 srw but they give you a good idea on how the truck is factory rated. Send me a email if you like but by all means post a picture of this rig.
__________________
Thanks, Tim * VIN/Model Decoders * Power Team Charts (engine/transmission/gear ratio) * Post Your Pickup SPID ** Blazer SPID ** Suburban/Panel SPID * RTFM ... Read The Factory Manuals... download 'em here Highlanders ** Do you have a 1972 Plaid Pickup? ** Plaid Blazer ** Plaid Suburban |
04-28-2013, 09:06 AM | #4 |
Registered User
Join Date: Dec 1999
Location: Austin, TX, USA
Posts: 7,728
|
Re: Need info - replacing 16.5 inch wheels and old style tires.
I ran 265 75 16 E rated Michelin LTX on my 70 GMC 2500. I had them on 16x7 Alcoas. This was an excellent combination that gave a 3400 GVWR per tire.
__________________
44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax |
04-28-2013, 09:30 AM | #5 |
Registered User
Join Date: Mar 2011
Location: Dallas, TX
Posts: 39
|
Re: Need info - replacing 16.5 inch wheels and old style tires.
|
04-28-2013, 04:47 PM | #6 |
Special Order
Join Date: Nov 2004
Location: Mt Airy, MD
Posts: 85,851
|
Re: Need info - replacing 16.5 inch wheels and old style tires.
I would look into tires for the 8" wheels in a load range E,just not sure what profiles are available anymore. I would consider 16",and 17" as well,if it get's you the dimensions you want. I'm thinking you want a 9"-10" tire that is 31"-32"
__________________
"BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~ |
04-28-2013, 06:39 PM | #7 |
Registered User
Join Date: Feb 2008
Location: Fort Sumner, NM
Posts: 299
|
Re: Need info - replacing 16.5 inch wheels and old style tires.
That would be 265-75-16E or 265-70-17E both available in many makes and tread patterns.
|
04-28-2013, 09:01 PM | #8 |
Registered User
Join Date: Mar 2007
Location: San Pedro River, SE Arizona
Posts: 734
|
Re: Need info - replacing 16.5 inch wheels and old style tires.
A lot of insightful info here - thanks. I am a bit boggled with the varying perspectives, but will get focused with your help. Will measure and post the wheelbase (feel sure it is not more than 133"). Also will post a pic of the rig if you wish, although I have not yet gotten all of the trim/lights on after the paint work.
The camper company, Alaskan, says that this 8.5 to 9 ft. camper weighs about 1500 lbs. dry. I will search out the avg. weight of an 8.5 ft. ute bed - this is a substantial unit, so maybe will have to add some for that. This truck rolls and balances very well with the current wheel/tire combo. That is not an issue. But, I have been told (by tire dealer) that it is not so easy to get new 16.5 tires that run nicely (bumpy?), that the width options are limited, and that they are more costly per tire. (Is this true?). As you can see at the bottom, a lot of trucks live here and, in addition to the 16.5 tire issues noted above, I keep trying to get somewhat standardized on wheel/tire sizes. The remainder of the GM trucks are on 16" wheels (except the C80 and the big GMC aerial) and almost all are on 235/85s. Also, I do have a couple of decent 16" 8 lug wheel sets ready to use. It would be nice to have one size all the way around so that one spare would fit both ends, and would prefer to be at 16" for the reasons noted. But, I do not want to screw up the running aspect of this rig just for those purposes. If I can identify one 16" tire size/rating that will properly handle the weight/footprint needs, that will be good. For those of you who know 16.5 tire issues, are the above noted cautions accurate, or should one consider just buying new 16.5 inch tires for the current wheels? Might the current 7.50x16.5 tires be on 9.50 rims? I have some other 16.5 wheels around here in addition to the 5 on this rig. When I get the sizes sorted out, I will let those interested know. Thanks again - further insight will be appreciated.
__________________
CCCC 67 Sting Ray Coupe 327 4sp; 68 K10 Suburban 327 4sp; 69 K20 Lifted 383 4sp; 69 C80 Fire Truck 478 V6 5sp/2sp; 69 C20 Longhorn 327 4sp; 70 C30 Wrecker 350 4sp; 70 C30 Flat Bed 350 4sp; 71 C20 LWB 350 4sp; 72 K5 Blazer 350 4sp; 72 C30 Flat Bed Gooseneck Hauler with sleeper 350/TH400; 72 C20 Longhorn 402 4sp; 52 Mack LTL Supercharged Cummins 5sp x 3sp; 01 Dodge 5.9 HO Cummins 6spd; 02 Safari Trek 2430 8.1 Vortec on Workhorse Chassis; 03 Silverado 2500 HD 4wd Duramax/Allison Moved but still in the family 70 C20 Custom Camper 350/TH350; 72 K5 Blazer CST Highlander 350/TH350 Recently sent to new homes 72 C30 MoHome 402 4sp; 72 K5 Blazer Conv 350 4sp; 75 GMC 6000 Aerial 350 w Allison; 72 GMC 3500 Utility 350 4sp; 70 GMC 3500, 350 4sp |
04-29-2013, 02:44 AM | #9 |
Registered User
Join Date: Feb 2008
Location: Fort Sumner, NM
Posts: 299
|
Re: Need info - replacing 16.5 inch wheels and old style tires.
I believe that a regular highway tire or all season tire is getting really tough to find and therefore really expensive in 16.5 I agree that you can't find many width options in that type of tire. If you can live with an all-terrain then there are still lots of choices and I've found the 16.5's to run cheaper than the same size tire in 16. I just bought some BFG 35x12.50-16.5 and they were about $50/tire cheaper than a 315-75-16 which is the same diameter and width. The 12.5 width would be really nice for spreading the load. The BFG's are only D rated and you'll want E's which you should be able to get from Firestone or Toyo. If you go 16's then there are a lot of 265-75-16E's out there because that was an OEM size on many trucks before 17's got popular. They would be about 31" tall and 10.5" Wide. They're about the same height as your 235-85-16's but with more width. It is doubtful that you have 7.50s on your wider rims because that would defeat the purpose of the wider rim.
Also have the name of a good tire outfit in ABQ if you want it. |
04-30-2013, 11:19 AM | #10 |
Registered User
Join Date: Mar 2007
Location: San Pedro River, SE Arizona
Posts: 734
|
Re: Need info - replacing 16.5 inch wheels and old style tires.
Thanks Bill72. I will look into the 265-75-16E and see if they would work on the width wheels I have available here. The 10.5 tread width would be nice all the way around as long as that width in "E" would handle the rear axle load.
I should have been more clear earlier. I have 12 inch treads on the wide rims in rear, but 7.50 treads on the narrower wheels in front - but have not had those front wheels off to determine rim width. Was just wondering if those with the 7.50 tires might be on the 9.50 wide rims that guys here are seeking. Your info on the 16.5s is very good and helpful. I have not ruled out the 16.5 route and probably would like those 35x12.50-16.5 Es on the rear. But, would need a new spare, the same width as the narrower front tires, that also (diameter) would work on the rear if need be. Any idea there. Thanks so much guys. Any additional will be appreciated.
__________________
CCCC 67 Sting Ray Coupe 327 4sp; 68 K10 Suburban 327 4sp; 69 K20 Lifted 383 4sp; 69 C80 Fire Truck 478 V6 5sp/2sp; 69 C20 Longhorn 327 4sp; 70 C30 Wrecker 350 4sp; 70 C30 Flat Bed 350 4sp; 71 C20 LWB 350 4sp; 72 K5 Blazer 350 4sp; 72 C30 Flat Bed Gooseneck Hauler with sleeper 350/TH400; 72 C20 Longhorn 402 4sp; 52 Mack LTL Supercharged Cummins 5sp x 3sp; 01 Dodge 5.9 HO Cummins 6spd; 02 Safari Trek 2430 8.1 Vortec on Workhorse Chassis; 03 Silverado 2500 HD 4wd Duramax/Allison Moved but still in the family 70 C20 Custom Camper 350/TH350; 72 K5 Blazer CST Highlander 350/TH350 Recently sent to new homes 72 C30 MoHome 402 4sp; 72 K5 Blazer Conv 350 4sp; 75 GMC 6000 Aerial 350 w Allison; 72 GMC 3500 Utility 350 4sp; 70 GMC 3500, 350 4sp |
04-30-2013, 12:28 PM | #11 |
Registered User
Join Date: Feb 2008
Location: Fort Sumner, NM
Posts: 299
|
Re: Need info - replacing 16.5 inch wheels and old style tires.
My guess is that your 12" wide tires are on the 9.75" wheels that are sought after and the fronts then would be a narrower wheel. Maybe not though so its always best to measure. The 12.50 wide tires in an E rating that I was referring to were the 315-75-16's. I wasn't having much luck finding an E rated 16.5 with any height to it without going to the Goodyear military tires and those were too tall for the look I was going for. Another great option that is becoming difficult to find is a 255-85-16E. That is about 33"tall and 10" wide. They do fine on a 7" rim and if you want the stock look you can still find the Ford 16x7's out there. If you found 5 then you coud stick a matching spare in your carrier and maybe still have the ground clearance you want. If you go with 255's and don't mind shelling out the money, look at the Toyo M55's.
|
04-30-2013, 12:36 PM | #12 |
Registered User
Join Date: Jul 2011
Location: WV
Posts: 946
|
Re: Need info - replacing 16.5 inch wheels and old style tires.
As the rest of the "herd" is riding on 16's, I think I would stick with them. I would go with either a 245 or 265 profile. Also, if you are interested in keeping stock parts for a restoration at some point, I might not toss those rims. There was an option for wider tires on the back according to the 72 Chevy info I have. They ran a 10.00x16.5 on the back.
__________________
72 GMC C2500 402/Th400 first truck (still have) 77 GMC C3500 CC dually Sold 70 C50 dump truck "Rusty" 87 K10 Suburban Sold 93 K2500 xcab 6.5TD 96 GMC K2500 Suburban 6.5 TD |
Bookmarks |
|
|