Hey guys, got a quick little question for you. So I am doing a 9" swap on the rear. Been to two junkyards so far and I think what I am going to do is pull a longer axle from a full size car or truck and narrow it to the size of a mustang rear using the currie ends. My question is: is the pinion offset on the mustang the same as on the maverick? My plan is to make a carbon copy of a mustang rear and then weld in new perches to my current spring location. You might be wondering why not just go carbon copy of the maverick rear? Well because the maverick axle has too little backspace for a wheel. So I can't go more that 3.75" backspace, if I space my axles out with a new rear I can use pretty generic wheels. Most wheel companies make zero offset wheels, so if I go 17x8 or 17x9 I can fit it with no problems.
Sounds to me like a large amount of effort and expense to get an increase in back spacing. Changing the backspacing won't allow you to run wider wheels. Do you need the 9 inch because you are making big power? Are you running 4 lug wheels and want to go to 5 lug? What is the purpose of this swap? The back spacing on the 15 X 8 inch wheels of my `72 Comet is 4.25 inches with room to spare. Several members on this site are running with 4.50 backspacing wheels. I believe you need to re-measure your backspacing.
I don't see it as too much effort. Either way you cut it, a 9" rear is better than an 8" rear. So if I am doing the swap, I might as well make it fit a more standard wheel. I can buy a different wheels, unfortunately odd back spacing 17s are north of $250 a wheel. I need to run a 17 because of the big brakes I am using in the front and in the back. And I think there is a rule of thumb on tire size based on the amount of power a car makes. My 180 hp audi has a 205 wheel, my bmw with 280 hp has a 255 wheel, I have owned a car that had tires that were too small and if I left first gear a little hard or left the light anything but gingerly, it would chirp. I don't want that. Currie sells nice housing ends that slide right over the axle tubes, so if I make my cuts right, the only thing I will be welding are the ends and the new leaf spring perches. I might even order the whole rear end from Moser if I can get an answer on my pinion offset question... I guess I can take my question to VMF or something.
HI Ivan. I don't think his response was meant to disaude you at all from upgrading to the 9".. more just towards helping you clarify what the actual backspacing allowance you have to start with on the 8" setup you currently have in the car right now. The 4.25- 4.5" neutral backspaced wheels are actually the defacto size for many of these older cars and the wider rearend will just push you towards to increased offsets of the more current late model sizing, is all. I myself like the deeper dish look but it's purely a personal preference kinda thing in the end. A centered wheel also has less potential runout and balancing issues.. but again, it's just a preference thing because obviously many use the newer wheels without issue. Either way you go here, unless you move the chassis's original leafspring mounting points.. you're just robbing peter to pay paul and the wheelwell of this car will only swallow up what can fit in the available space anyways. Are you planning on making enough power to really require the 9" rearend?.. or you are simply upgrading the 8" rearend anyways and figured what the heck.. why spend the cash there and may as well go all in with the bigger and heavier 9" setup?
I have a 70 Mustang 9" in mine, about 2" wider on each side than the Maverick rear. To get more backspace I had this place widen my wheels 2" to the inside, now they're 8" wide with 6" backspace. http://www.weldcraftwheels.com/ Probably costs a little more now but back when I had them done it was $100 a wheel. They can also make wheels narrower.
If you are still considering a 9", try and look for a 1975 to 1980 Ford granada or monarch with a 9" in it? They come either drum or disc and housings are more beefy then a mustang one. I have these in both of my mavericks (drum style) and the pinion angles are good as is or about same as maverick housing. the Housings are about 1/2 inch longer per side over stock maverick. I run 8 inch wide rims with a 4.5 back space on one maverick. The only problem is they are harder to find now and have to find yards that keep the older cars?
