Tire size recommendations for "assertive" 1965 Special billy-goat wagon.

Discussion in 'The Hides' started by elagache, Sep 26, 2013.

  1. elagache

    elagache Platinum Level Contributor

    Dear V-8 Buick tire size experts,

    Today was a major milestone in the story of my trusty 1965 Buick Special wagon. I got to drive her for the first time!! :) It wasn't as nice an experience I wanted, but it will take a while for the EZ-EFI system to tune the car to run smoothly, so a rough ride was to be expected. However, there was a very critical reason for this trip: I wasn't sure Biquette could get down the steep slope of our driveway with the new hitch!! :shock: Fortunately, she made with without any problems at all! :TU: I promise to post a few photos of the first outing soon.

    However now that the suspension doesn't need any more monkeying with, it is time to get serious about selecting new wheel rims and reasonably sized tires.

    *Heavy Sigh*, I'm resigned to replacing my almost new 14" rally wheels with essentially the same wheels in a 15" width from Wheel Vintiques:


    They come in only two widths: 7" and 8". Since I would much prefer to have the same tires on all 4 wheels, I really have no choice but the the 7" width - don't I? :confused:

    As for tires I really would like to keep the car's mid-1960s look. That seems to leave me no choice but to go with some sort of speciality tire maker like Diamond Back Classic Radials. They remanufacture modern tires to look like classic tires. I see that you can get BF Goodrich Radial T/A with just about any combination of Redline, Goldline, Blueline, and wide or narrow white wall. This page is only a partial listing of the choices:


    You can download their catalog for more details:


    That still leaves the question what sized tires? As said, I would prefer to have all 4 tires the same. That means I want a tire that will easily move in the front wheel wells without binding. I don't intend to race the car, so the goal here is good all around traction and eventually the ability to handle a small (16' - 20') Airstream travel trailer. My buddy Michael (64 Skylark Mike) suggested sizes in the range of: 245/60R15 or 255/60R15 on the 15 x 7 rally rims.

    What do you'all think? What is too big for a the front in a 1965 Special/Skylark? What do you think about the BF Goodrich Radial T/As? Does anybody know of another performance radial that can be purchased as a narrow width white wall? Anything else I should be considering with regards to billy-goat wagon tires?

    Opinions solicited!! :Smarty:

    Thanks for all the good advice already given!! :TU:

    Cheers, Edouard :beer
  2. jhonjhon

    jhonjhon Well-Known Member

    i don't know about tire size but check with steve caruso for the wheels first, just got 4 and they are extremely nice and i liked to help out the little guys like myself. here is his web site http://carusoperformance.com/index.html

    BUICKRAT Torque Rules!


    15x7 rims will look good. Not so sure on the bfg's, though. I have them on the front of my beast and they do not handle all that well. (nor do the shredded Kelly Chargers on the back)

    Wait until you get the driveability issues taken care of, then decide on what you want for tires/suspension. Put some miles on it, get the bugs out. :bglasses:

    Once tuned properly, that engine is going to turn into a Wildebeast when you hit the go pedal. Pitch, 'roll, and yaw will suddenly take on new meaning. :shock:

    You will find that you are severely "traction challenged" :TU::TU::3gears:
  4. Sportwagon400

    Sportwagon400 Well-Known Member

    i run 255/50/16 on the rear 16X8 with 5 1/2" back spacing and 215/60/16 on 16X7 with 4 3/4" back spacing works great i also have a 69 GS 3.31 posi rear if you have the stock rear 5" back spacing will give you the best fit

    back spacing is KEY on this car you need minimum 5" in the rear to run any size tire and if your front is a low as mine you need 4 1/2 minimum and no wider than 215 to clear

    this works with no rubbing and my cars are all fairlly low


    Attached Files:

  5. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    According to the 65 Chassis manual, the stock tire size for that wagon was a 7.35-14, and optional was 7.75-14. This chart can give you the equivalent modern tire alternatives.


    The tires were relatively short, about 25". If you go to 15" rims, the tires will be considerably taller, and that will alter your speedometer calibration and final drive ratio. In addition, you may need custom back spacing to get the bigger tires to fit. I would look at the 14" rims again, and do some careful measuring to see how much room you have inside and outside the rim width. You can then estimate how wide a tire will fit in the wheel well. The number after the P is the section width in mm. Just divide by 25.4 to get to inches.
  6. Sportwagon400

    Sportwagon400 Well-Known Member

    Good info Larry but 14" tires are harder to find and usually a poor handling tire. My 255/50/16 are 26" tall and look great a 245/50/16 is 25.6". Looks are important as well and big tires look mean and handle better to boot

  7. elagache

    elagache Platinum Level Contributor

    Thanks for the tips! (Re: Tire size recommendations for billy-goat wagon.)

    Dear Larry, Ken, and V-8 Buick tire experts,

    Thanks for digging up that info for me!

    Biquette will need her speedometer to be recalibrated anyway. It is already off because of the 200-4R tranny and we still need to decide on the rear end ratio. So going with bigger tires isn't adding any work that wasn't already in the queue.

    That is what I have been discovering also. The tire selection for 14" rims had really gone down to mostly tires designed to resemble the classic tires of the period. I bit the bullet yesterday and ordered the 15"x7" rims yesterday. There are some tires floating around Orinda Motors that can be used to test for clearance issues. So odds are Biquette will indeed end up with something similar to what you have Ken except on 15" instead of 16" rims.

    Thanks again for a good advice!! :TU:

    Cheers, Edouard :beer
  8. wkillgs

    wkillgs Gold Level Contributor

    I run 235/60-15 front and 255/60-15 rear mounted on 15x7 Buick mags on a couple of my 66 GS's. Fender clearance can be snug on the back at the wheel lip on one side, my finger tips just fit between tire and wheel lip on one side, a little more on the other side.
    I've read a few report that 65's have a bit more clearance there than 66-67.

    I prefer 15's and a tall tire as I just think it looks better on a fairly large car.
    If you want all 4 the same size, 245's might fit in the front (possible rub on turns), and 235's start to get a little short and may look small in the rear.
  9. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    Re: Thanks for the tips! (Re: Tire size recommendations for billy-goat wagon.)

    Ed, I would not have ordered the 15 X 7's as they come from WV. They will have a BS of 4 1/4-4 3/8", and that will compromise your tire choices. I believe you need more BS. You will have less space on the outside of the wheel than the inside. I think you will be better off getting some Buick Rallyes made with more like 5" of back space. I might be wrong, but I think the 65's need more back spacing. That will be the critical part. 15" wheels will look great on the wagon for sure, but it is absolutely essential that you center the wheel in the wheel well. See if someone will lend you a stock 15 X 7" Rallye wheel. Mount it and measure from the inside edge, and outside edge to see how much room you have and how centered the rim is. I'd hold up that order until you do so. You really are taking your time and being careful up to this point. Make sure you aren't making a mistake here. JMO.
  10. wkillgs

    wkillgs Gold Level Contributor

    Re: Thanks for the tips! (Re: Tire size recommendations for billy-goat wagon.)

    The 15x7's on my 66's have 4-3/8" backspace, a little more would be ideal.... 5" bs on a 7"wheel, or 5.5"bs on an 8" wheel.
    Do you still have the original 8.2 inch rear? A later 8.5 rear would be wider, and an early Chev 12 bolt will be narrower.....that will affect wheel choice.
  11. elagache

    elagache Platinum Level Contributor

    Now he tells me!! (Re: Tire size recommendations for billy-goat wagon.)

    Dear Larry and V-8 Buick tire experts, . . . . .

    [​IMG] . . . . . Where were you on Friday afternoon!! . . . . . :Dou:

    The trouble is . . . . . they are already here! Summit did their delivery wizardry and the wheels are in my garage.

    I'm sure you are correct, but after all this is truly the family station wagon - not a high performance car. I'm not trying to achieve extreme speeds or anything radical like that. I'm even resigned to trimming back the size of the trailer I can tow. I may need have to settle for 245/60R15 so something like that. If I cannot get the most tire for my trusty wagon, I'll have to compensate in other ways.

    Thanks for the help though! :TU:

    Cheers, Edouard :beer
  12. sean Buick 76

    sean Buick 76 Buick Nut Staff Member

    Re: Now he tells me!! (Re: Tire size recommendations for billy-goat wagon.)

    Confirm the width between the tire beads and ensure it is 7"

    Also measure the backspace which is the depth from the back of the wheel mounting surface to the deepest part of the rim...

    With those two measurements made we can find out if they will fit well or not... If not you could still return them as they are not used yet.
  13. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    You may not be able to fit P245/60R-15 on the wagon with 4 1/4" of back spacing. It may need 5". If you mount the wheel on the car, you will be able to see whether there is enough clearance for the tire. 245mm section width is 9.6". That means you need at least 1.3" of clearance on the inside and outside of the rim. Measure.
  14. Sportwagon400

    Sportwagon400 Well-Known Member

    you need 5 5 1/4 or 5 1/2 back spacing on a 8" rim to run 245 or 255 tires the problem is the outer wheel well not enough room i have a;ll three of these rim sizes and have had all of them on my 64/65 skylarks and wagons 66 /67 different 68/69 different 70-72 different

    i have owned all of these cars and I KNOW WHAT fits with no rubbing

    Attached Files:

  15. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    He currently has a 7" wide rim now. What back spacing will he need to run the 245's? I'm thinking more than the stock 4 1/4- 4 3/8"
  16. elagache

    elagache Platinum Level Contributor

    Biggest tires for 15"x7" ??(Re: Tires for "assertive" 1965 Special billy-goat wagon.)

    Dear Mr. Buick, Larry, and mid-60s Buick tire experts,

    Sorry for not getting back to you'all sooner. My hard drive started to fail Tuesday night and I wasn't able to get a replacement until yesterday afternoon. So I've been really limping along without my computer.

    First, thanks for the feedback! That's exactly what I was looking for!

    So does anyone know what is the largest tire I could realistically put on the 15"x7" Wheel Vintiques wheels? They are rated a nominal 4" backspacing. Greg borrowed some other rims that had a 225/60R15 and they are already rubbing, but the back spacing on those rims isn't deep enough. The Wheel Vintiques wheels are getting an opticoat treatment right now so they cannot be used for testing.

    Sorry, for asking. I had hoped to just ferret out the answer from previous postings. However, the boards own search works very poorly and since Google has changed it search algorithm, it doesn't work well at all for searching the board. However, no worries - now Google happily suggests advertising chosen carefully to interest V-8 Buick members!! :rolleyes: :spank:

    *Heavy Sigh* [​IMG]

  17. bobc455

    bobc455 Well-Known Member


    It sounds like this is more of a family car than a race car.

    Therefore my personal preference would be to go with a skinnier tire- these look more "correct" and I think you'll like the ride more.

    Yes, a narrower tire might not corner as well- let the racecars do that. For a family truckster (especially if driven in the rain), I would go very conservative.

    A 245 or even 235 sound wide for me (as I understand your usage of the car, anyhow).

    Even my drag radials are only 235/60/15's.

    Just my opinion...

    -Bob C.
  18. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    Re: Biggest tires for 15"x7" ??(Re: Tires for "assertive" 1965 Special billy-goat wag

    What was the back spacing on the rims that Greg borrowed? Find out. I think you should return those WV wheels before you paint yourself into a corner. The 15 X 7" WV wheels have 4 1/4" of B.S.. From what I am reading, that's not enough for your 65 wagon. I am trying to stop you from making a mistake. Think about it. The section width of a tire is the distance measured between the side walls of the tire horizontally. That is the number after the P, measured in mm. The above tire is 225 mm wide. That's 8.8" wide. That means that they extend almost 1" on each side of the 7" rim. 7" is 178 mm. How thin of a tire do you want to use? If the wheels that Greg tried have a lot less back spacing, then maybe you will be OK. Have Greg measure the B.S..
    Last edited: Oct 4, 2013
  19. GS Jim

    GS Jim Platinum Level Contributor

    Hey Ed, I offered you some parts about a Year or so ago, You declined and said you wanted to keep it Stock looking. What happened Man? Same thing that happens to the Rest of Us? Gotta Have More Power? I feel Your Pain. :TU:

  20. elagache

    elagache Platinum Level Contributor

    Reinventing the 1960s SUV. (Re: Tires for "assertive" 1965 Special billy-goat wagon.)

    Dear Bob, Larry, Ponch, and mid-60s V-8 Buick fans,

    Sorry, I need to apologize. This thread didn't state very clearly what I was really looking for, because I hadn't thought through all the parameters I needed to cover. What I really was looking for is two kinds of information on tires:

    • What was the absolute limits on tire sizes, so that I would know what to avoid.
    • Recommendations on reasonable tire sizes for what I want to use my trusty wagon for.

    I think your advice is close to the mark. My goal isn't factory specs, but I very much want the car to look like it just traveled through a time-warp from 1968 say. So, I want a tire that will look as close to a 1960s era tire, but provide the handling and safety necessary for what I want to use the car. It isn't just cruising about town, but my towing aspirations aren't so enormous that I need huge tires. I just checked and for example the 1970 Buick Estate Wagon had P225/70R15 tires. That was a 5000 lbs. car which I assume could tow at least as much, if not more like 10,000. It also was big-block powered.

    Well Larry, if *you* were going to drive my car, I more than agree with you! However, I'm still going to be Mr. Meek when it comes to driving this car. The plan is to have a very tall rear end ratio, something like the 2.73 which was standard on the 1970 Estate wagon by the way. So arguably, I'm "wasting" (from the racing perspective) the potential power of Jim's engine. What I was always looking for in this engine was torque, not horsepower. Moreover, even that objective is to be used in a way that is unorthodox by typical configurations of Buicks on this board.

    I've only driven the car 6 miles, but even with the utterly whimpy 205/70R14 tires that are on the car now, the car almost as benign as I remembered her. That was with a particular bad tune because Greg had just zapped the EZ-EFI tune data in order to reprogram it to operate the electric fans. About the only way I could get myself into trouble is if I accidentally apply a jerking pressure on the accelerator and the new accelerator is much stiffer than the old one.

    Let me say that I have a lot of respect for your quest for ever greater speed. However, that's just not me.

    I don't remember what you offered me, but honestly I'm trying to do something with this car that must seem very odd to most of you. My goal is to modernize the car so that I can keep use it as I always have. It is very different to have lived with a car all your life than to jump from one car to another and then one day decided to go retro and pick up a piece of 1960-70s machinery. I not saying at all that I don't want to modify the car - my Dad and have been modifying the car since we bought it! Remember, this car didn't even come with rear seat belts, If I wanted to go stock I would have to remove them!!

    This engine is really a bold experiment in trying to make a 50 year old car compete modern cars in a very difficult realm: cruising out on the open road. In a way, what I've tried to do is infinitely harder than an 11 second 1/4 mile. It is certainly an open question as to whether Biquette will succeed as a car that can be driven a few thousand miles to visit the country in a way that is truly pleasant at least somewhat economical. That is what I'm trying do to. Stay tuned to see if I succeed!

    Cheers, Edouard

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