You definitely need 5.5” backspacing to tuck it under there. Anything less is going to push it out too far for sure.
5.5" back space on a 10" wide rim is bare minimum on a 70-72 car. The 68-69 cars need more I believe. Then you have the possibility that there is more room on one side than the other. That is pretty common.
I’ve worked with both 68-69 and 70-72. They will both take 5.5” backspace. 5.75” would be ideal,but they are no production rims made with that dimension. If you have the stock rearend,you would also hit the shock bolts with anything deeper,but you will also start rubbing the frame or inner wheelhouse. Here is a stock wheelhouse/frame and stock rear with a 5.5” backspace.
So that is a 15"x10" wheel with 5.5" and what size tire??? I run a 29x10 on a 15x8 with 4.5"bs I'd love to see if I can fit hoosiers 29x10.5x 15 stiffwall tire. Or a Mackey protracted radial 29.5x10.5x15
Brian, looks like you have the springs shimmed up like I have in my car. I bought my car like that, but up until then, I had never seen the springs shimmed at the bottom like that.
This is more of my beater right now. I’m about to take it all apart,do a chassis swap,and make a real car out of it. Those springs are only about 10” tall. Not sure what they are or where they came from,but they are headed to the scrapper shortly. The tires are 325/50/15 drag radials.
Overall width is about 13”. Diameter is right at 28”. Tread width is 11.25”. I don’t think this tire will squeeze under a 68-69,as I think the wheelhouse is a little narrower. Another good tire is a 295/55/15. That one is 28” tall,with a 10.5” tread width,and about 12.5” overall width. Do NOT confuse that with a shorter 295/50/15 or the taller 295/65/15.
I think that's where my section wall width issues come.......I run a taller tire and that tends to make the middle fatter. That 29x10.5-15w hoosier I think I will try next is 29.3 tall, 13" section and 11 tread and a stiff sidewall My 29x10-15 are. 29.1 tall, 11.9 section and 10 tread But im certain I'll need a 10" rim for the new tire not just the 8" I have
https://holeshotwheels.com/ Great company to deal with. They will make what you need. you may also need to massage the inner wheel well and outer a bit. but it can be done.
I like when they hook more than likely. I started running drag radials when BFG made their drag radials over 20 years ago. I had great luck with them,and I continued to use them when the Mickey’s came out,simply because I didn’t have a reason to switch. After awhile,I knew a hunch of guys running the Mickey’s,and they kept hassling me to switch over,so I finally did next time I needed tires. I haven’t had issues with them either. I’m putting a lot more power down now,and it’s hard to say if the BFG’s would have worked or not. They don’t even make them anymore. Even the original Mickey’s are different now. For the cool factor,I always like the Mickey Thompson I-wraps. I just thought they looked cool.
I run Hoosier radials on Chevelle 295/65/15. They fill wheel well nice. 275/60/15 on Buick. Have the new radial tread. Looks aggressive but in reality more street worthy w the tread pattern. The Hoosiers are definitely narrower than mickeys in 295s. My friend runs them on his cutlass. On the Mickey I’s. I melted many a set back in the day on the streets.
I have never run any of drag radials, but had reps from hoosier and mt tell me they hook till they don't, and if they don't getting them to recover on that pass is very very hard to do.......unlike a pure slick that will often dribble or spin a few revs then hook up on its own. I dont know if mt pro bracket radials would be the same way or not. I have been fighting my slicks getting balled up on the sidewalls for a long time.....tubes helped some....I'm running 18.5 psi. Much less it gets drastically worse....but much more hurts bite. I think the stiff sidewalls would really help me but the sizes are not very plentiful. I also wonder if a 10" wide rim on my 10" wide tire would help over my 8". Judt haven't had any luck finding a good used pair of weld pro stars to try.....hate to spend 700+ at a try
I just want to clarify, are those pics above of a '69 with 10" wheels. I see a lot of info but what pertains to the '68-69's?
My pictures are a 1970. Yes,the outer clearance would be different,but I was trying to show the inner clearance with a 5.5” backspace wheel in a 68-72 inner wheelhouse and frame.
