Wheels & Tyres

[Darren Dorcich]

I have had a set of original Minilites that I was going to put on my 1970 Fastback.  Fitted them the other day and they are too wide.  I have 15x8 on the front which are fine but the 15x10's on the back are too wide.  I can either flare the guards (which I don't want to do) or modify/shorten the diff.  Not sure I want to do that either.  So I am in the market for a set of rims and tyres and need some help working out what to do.  So can you please post up your wheel and tyre combos on your cars please.  Can you let me know sizes you have used and any modifications required.  My car is a Grabber Blue B2.  Thanks.

[BAC]

Have a read of this - very informative:

http://www.mustangandfords.com/how-to/wheels-tires/mump-0507-ford-mustang-large-wheels-fit/

[ants]

How much do the wheels stick out past the guards?
Can you machine some of the boss off the back of the wheels?
I have Superlites on my '70 Mach 1 and had to narrow the diff 35mm per side and roll the lips to get them under the guards.
If you don't want to cut the original housing, why not get another one to modify so you have always got the factory diff to put back in.
I'm biased but I think Minilites are the best wheel for a muscle car of that era.

[Herman]

Hi DarrenD,

Being your vehicle is a B2 I would keep the car unchanged/original as much as possible but that's personal preference.  However can I suggest you call Robbie Tuckett from Tucketts Tyrepower in Hastings and he can give all the information/options.  In addition Robbie has worked on Mustangs for many years, is MOCA Vic member and has worked on my cars overs the years.

Herman

[shaunp]

Performance wheels do Super lites and will do them in a custom off set to suit your needs. lots of the TCM & Tran-am cars are running them.

http://www.performancewheels.com.au/product/superlite-15/

[Dwayne]

Getting the correct offset/backspace is the key to positioning the wheels in the perfect spot within the guards. Offset and backspace are two methods of showing the same thing ... where is the wheel mounting face (ie boss) positioned in your rim?

• Backspace is measured in inches from the back of the rim. Modern cars have big backspace as distance from back of rim to wide brakes is big, whereas our classics have small backspace (ie 3.5"). The smaller the backspace, the bigger the lip
• Offset is measured in mm and is a positive vs negative from the centreline of the rim. Modern cars have their brakes out wide, so have a positive offset (ie+35mm), whereas our classics have brakes inboard so negative offset (ie -10mm).

Most wheels have their size and offset/backspace stamped on the back. 


If you then measure your wheel on the car record how much clearance you've got inside and outside, you can work out if your wheel need to go in (smaller backspace) or out (bigger backspace).

These measurements can also be put into a calculator like this one:

http://www.tyresizecalculator.com/tyre-wheel-calculators/wheel-offset-backspace-calculator

[DAA]

Sorry, can someone tell me what a B2 is?

Still learning. Thanks.

[barnett468]

Sorry, can someone tell me what a B2 is?

Still learning. Thanks.

There is no such thing. It is slang for a boss 302...or its the acronym for a ww 2 b2 bomber or a 1972.nissan honey bee. 

[DAA]

Thanks barnett468,
There are a few instances of B2 on the net, but I couldn’t find an explanation.

(Coincidentally, I got my 1975 licence in Mum’s Datsun 1200 - sort of a precursor to the HoneyBee by the looks!)

[Reborn67]

Are you thinking what I’m thinking B1?

[GLENN 70]

Do not flare the guards ,do not shorten the diff , buy a pair of wheels with the correct offset .  Ok I suppose you could get a shorter diff but don't shorten the original 9 inch . Question is it a 9 inch ? . If it isn't and an 8 inch just buy a 8 inch out of a 65-66 as they are 2 inches narrower than 67-70 diffs .  57.25 compared to 59.25 inches .

[Dwayne]

What brand are the mini-lites? The Trans-Am Race Engineering ones can have some of the boss machined off to give you the correct offset.