Hello all, I am looking at getting some much wider tires for my 68 Skylark. I have been looking at other threads and done my own measurements myself, however I am still concerned about buying rims that may not fit in the end, without modification. The measurements I have: I should have 6 and 3/4” on the inside and 5 and 3/16” on the outside (towards the quarter lip) The 6 and 3/4” measurement I am getting on both sides is from where the wheel well sticks out as pictured. I am not sure if this is actually where my tire would hit or not, but that is the first part I’m thinking it could hit. I am looking at getting 18” wheels to clear the shock that are 9 inch wide with 25mm offset (6inch backspacing). From those calculations I think it would fit but be close with a 275 and maybe a 285 series tire. Will post a picture of section widths I’m looking at also. If anyone can impart some wisdom or has tried this or a wider type of setup without modification, it would be greatly appreciated. Thanks, Tony
Here is a set of tires I was looking at, section width is 10.9” on a 9.5” wide rim. Also if anyone has any input/suggestions for the front wheel/tire combo, it would be greatly appreciated! Thanks, Tony
The 68-69 wheel wells are less generous than the 70-72 wells. You are trying to stuff the widest tires you can into them. I believe you have it about right with 6" BS on a 9" wheel, but I am afraid no one can guarantee that you will not have some clearance issues. Every car is a bit different depending on the exact fit of the body on the frame. You are in the ball park. The 70-72 needs 5 1/2-5 5/8" BS on a 10" wide wheel. Good luck.
My 70 had 13.25" total clearance inside and out, I run a 295/18. You are just under 12" total, I would not go over 275 sw. Based on your measurements, looks like 20 to 25 mm offset will center your tire. I would lean toward 20 mm o/s bc of how the axle will articulate on compression. I would double check measurements before you buy. Easy enough to make a 27" dia piece of plywood bolted to the hub, and check all clearances with plumb bombs, tape measure etc. I would also check clearance to the frame, just ahead of the axle about 10 to 12"
275 40R 18's--those are some tall, wide tires! You could play it safe like I did, and just cut out and radius the rear wheel wells so they match the front wheel wells.
Thank you guys for the info, will double check my measurements on both sides of car again before purchasing. Will be cutting out a diameter at 27” and also looking at possibly getting smaller diameter tire, looking more around the realm of 26.7” diameter or less.
