Author Topic: 66/67 Fairlane owners with relocated leaf springs: how much rubber can fit?  (Read 591 times)

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6667fan

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I had my leafs moved inward this fall utilizing a Crites kit. What size rubber on what rim width and back spacing can fit without further mods? Rather not start cutting out the inner fender or sectioning the frame rail. I have 9x28 slicks on Weld Wheels that are 8” wide with a 5.5” bs. I know I will need more back spacing than that based on how close the tire is to quarter panel currently.

Thanks
JB


67 Fairlane 500 482 cid 636/619. Tunnel Wedge, Survival CNC heads, Lykins Custom Hydraulic Roller, face plated David Kee all aluminum TL, Eaton Detroit True-Trac 4.57 9 inch
11.8 @122mph

TomP

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You will probably need to narrow the rear end just to be able to get the tire in and out of the car. The shorter rear end makes more space between the brake and fender to get the sidewall in.  The limiting factor for width will be the inner wheelwells and the bump stops. I cut the bump stop brackets right off but if you don't want to cut anything the 9x28 tires will need to sit pretty close to them to clear the fenders. 1/4" of room is OK unless you plan to slalom race it.

frnkeore

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The way I do it, is to take the tire off and then, with the jack under the axle, take a 24" carpenter square and butt it against the axle flange. Measure the distance, from the edge of the square, to all areas that encompass the tire, keeping in mind the actual section width of the sidewall.

I would subtract at least 1/2" from that measurement for the back spacing using the sidewall as the reference point.
« Last Edit: November 08, 2020, 01:43:56 PM by frnkeore »
Frank

6667fan

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Bump stops already gone, had to remove them just to make the 9 x 28s fit. I tried a 10.5” tire on an 8” back space wheel and the inner fender was interfering. I’m hoping a 10-10.5” piece of rubber with a yet to be determined amount of bs will fit w/o sawing inner fenders.
Thanks
JB


67 Fairlane 500 482 cid 636/619. Tunnel Wedge, Survival CNC heads, Lykins Custom Hydraulic Roller, face plated David Kee all aluminum TL, Eaton Detroit True-Trac 4.57 9 inch
11.8 @122mph

Posi67

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Fairlane's are always a tight fit and most wheels don't come with the back space you like or need. Also check section width specs on tires before you buy. Goodyears tend to be the narrowest for any given tire size. I have a 6" back space wheel that will only work with the Goodyear. Anything else rubs the springs hard.

I'd defer to TomP's advice. If there is anything oddball then he's tried it or modified something to work.

JamesonRacing

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I have my leaf springs on the inside of the frame rail, housing is narrowed a bit.  Running 15x10 wheels with 4.5" BS, and a 30x10.5 slick.  Plenty of rubber to run into the nines.  Had to tuck in the inside of the wheel housing and massage the frame rail at the back where it kicks back into the wheel opening.
1966 Fairlane GT, Silver Blue/Black 496/C4 (9.93@133)
1966 Fairlane GT, Nightmist Blue/Black 465/TKO (11.41@122)
1966 Fairlane GTA Conv, Antique Bronze/Black, 418EFI/C6
1966 F250 C/S, Rangoon Red, 445/T19
1965 Falcon Futura 4-door, Turquoise, EF! Z2363/4R70W

Jb427

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i use a home made jig to work out diff length made from 2 trailer axels and hubs and heavy wall tube so they can slide in and out some mounts so you can bolt it up to the springs then go see all your friends get a few sets of rims with backspace you like and some old tyres and go to town.

6667fan

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The 28 x 9 Hoosier is on an 8” wheel. I will have to learn if the larger rubber mandates a 10” wheel. If so, then the back spacing needed with my stock width housing will be the curveball. If I stick with my current Weld Wheels and pay attention to section width perhaps I can get 10” on my existing wheels. I will be checking recommended wheel widths for the rubber chosen also.

Thanks all
JB


67 Fairlane 500 482 cid 636/619. Tunnel Wedge, Survival CNC heads, Lykins Custom Hydraulic Roller, face plated David Kee all aluminum TL, Eaton Detroit True-Trac 4.57 9 inch
11.8 @122mph

manofmerc

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On my 67 comet I didn't have any problems with 9x28 on an 8" rim .It was when I went to a 9x29.5 that I went through much grief due to increased section width on the 9x29.5 .I narrowed my housing 7/8" if I hadn't done that the bigger tire would have never worked .The next set of 9x29.5 had a narrower section width at least 3/8" of an inch more clearance than the first set .I wanted a taller tire and they really work good and look better to me .But I really cant say the 9x29.5s work any better than the 9x28 .If you moved your leaf springs with that crites kit You might just get a 10" slick in there . There are lots of tools you can purchase to determine what wheel tire combo you can fit .Good luck Doug

Falcon67

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I run a 275-60x15 drag radial on the Falcon with stock spring location, 54" rear flange width, 10x2 drums, 4.5" backspace and a 1/8" spacer.  Clears.  That's a 28" tire with a 11.5" section, 9.8" tread. Rolled fender lips.  Should be very similar to a 66/67 Fairlane.

6667fan

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Re: 66/67 Fairlane owners with relocated leaf springs: how much rubber can fit?
« Reply #10 on: November 11, 2020, 04:48:10 PM »
I’m looking at 15 x 10 wheels now with a 6.5” back spacing. That should allow for a 28 x 10 slick on my Fairlane with the relocated leafs. Perhaps even 10.5. I don’t need to go taller and 29.5 rubber brings in additional problems.

Thanks all.
JB


67 Fairlane 500 482 cid 636/619. Tunnel Wedge, Survival CNC heads, Lykins Custom Hydraulic Roller, face plated David Kee all aluminum TL, Eaton Detroit True-Trac 4.57 9 inch
11.8 @122mph

JamesonRacing

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Re: 66/67 Fairlane owners with relocated leaf springs: how much rubber can fit?
« Reply #11 on: November 11, 2020, 07:06:27 PM »
I’m looking at 15 x 10 wheels now with a 6.5” back spacing. That should allow for a 28 x 10 slick on my Fairlane with the relocated leafs. Perhaps even 10.5. I don’t need to go taller and 29.5 rubber brings in additional problems.

Thanks all.

Adding height to a slick seems to be more beneficial for traction than width.  I used 11x28 slicks on 10" wheels and did not get the results I had expected.  Changing to a 10.5x29.5 launched the car quite a bit better, and was more stable down track.  Just my two cents worth.
1966 Fairlane GT, Silver Blue/Black 496/C4 (9.93@133)
1966 Fairlane GT, Nightmist Blue/Black 465/TKO (11.41@122)
1966 Fairlane GTA Conv, Antique Bronze/Black, 418EFI/C6
1966 F250 C/S, Rangoon Red, 445/T19
1965 Falcon Futura 4-door, Turquoise, EF! Z2363/4R70W

6667fan

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Re: 66/67 Fairlane owners with relocated leaf springs: how much rubber can fit?
« Reply #12 on: November 11, 2020, 10:28:38 PM »
Appreciate that David.
Maybe there is a 29” I can fit in there but I imagine it will lower trap rpm which was ideal with a 28” tire. I tried a 29.5 on a 10 x 15 with 8” of bs and I could not get it in there at all. A lot of interference on the inside wheel well. That is why I was aiming for 6” bs. I know you fit yours with 4.5 bs but I’m assuming your narrowed housing changes the equation.

Thanks
JB


67 Fairlane 500 482 cid 636/619. Tunnel Wedge, Survival CNC heads, Lykins Custom Hydraulic Roller, face plated David Kee all aluminum TL, Eaton Detroit True-Trac 4.57 9 inch
11.8 @122mph