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Matt300ZXT · 09-17-2010, 05:34 PM

Ok so I'm trying to do some measuring and figure this out on my own. I measured from a lip to a lip on the bed of my 54 (no fenders on it right now), which is about 1/2" difference from the actual outer sides of the bed, and it measured right at 51.25" give or take a 1/4". So we'll say a tad over 50" from one outer bed side to the other. If I run the less wide G-body rear end which is 58" instead of the 60.25" Nova unit, I can run wider wheels, assuming the wheel has more negative offset, pushing the bulk of the width of the wheel into the fender and away from the side of the bed, which gives more of the "deep dish" look.

So if my crappy calculations are correct, if bedside to bedside is roughly 50", and the G-body axle width is 58", technically I could run a wide a wheel as will fit in the fender, in relation to fender rubbing, as long as the wheel has about 3.5" of backspacing (to keep it away from the side of the bed)? However, if I run the Nova rearend which pokes out to nearly 61", I'd have 5" on each side meaning I would have to get a wheel with about 4.5" of backspacing to keep it away from rubbing on the sides of the bed?

Pardon the crappy Paintbrush drawing, but I'm using this to kinda help me figure out wheel mathematics. The 50" bed width and the 58" axle width, divided by 2 is where I'm getting the 4" of space between the wheel mount surface, and the outer sides of the bed, giving me the 3.5" or so of backspacing I'd need at max to give a little bit of clearance and to prevent rubbing.

Back when I was working on my 280Z and trying to find wheels, I used to know all this wheel math and was very good at it, but alas, that's been years ago and I forgot it all, so I'm having to re-learn it all.

Again, this is all theoretical in my head right now and may not work in the real world. I just want to know if my math and thinking is on the right path. Getting exact dead on measurements comes when I go to pick up whichever rear end I decide on, I just want to know if the way I'm using these measurments is correct.

09-17-2010, 05:34 PM	#9
Matt300ZXT Registered User Join Date: Apr 2010 Location: Chattanooga, TN Posts: 100	Re: Which of these rearends? Ok so I'm trying to do some measuring and figure this out on my own. I measured from a lip to a lip on the bed of my 54 (no fenders on it right now), which is about 1/2" difference from the actual outer sides of the bed, and it measured right at 51.25" give or take a 1/4". So we'll say a tad over 50" from one outer bed side to the other. If I run the less wide G-body rear end which is 58" instead of the 60.25" Nova unit, I can run wider wheels, assuming the wheel has more negative offset, pushing the bulk of the width of the wheel into the fender and away from the side of the bed, which gives more of the "deep dish" look. So if my crappy calculations are correct, if bedside to bedside is roughly 50", and the G-body axle width is 58", technically I could run a wide a wheel as will fit in the fender, in relation to fender rubbing, as long as the wheel has about 3.5" of backspacing (to keep it away from the side of the bed)? However, if I run the Nova rearend which pokes out to nearly 61", I'd have 5" on each side meaning I would have to get a wheel with about 4.5" of backspacing to keep it away from rubbing on the sides of the bed? Pardon the crappy Paintbrush drawing, but I'm using this to kinda help me figure out wheel mathematics. The 50" bed width and the 58" axle width, divided by 2 is where I'm getting the 4" of space between the wheel mount surface, and the outer sides of the bed, giving me the 3.5" or so of backspacing I'd need at max to give a little bit of clearance and to prevent rubbing. Back when I was working on my 280Z and trying to find wheels, I used to know all this wheel math and was very good at it, but alas, that's been years ago and I forgot it all, so I'm having to re-learn it all. Again, this is all theoretical in my head right now and may not work in the real world. I just want to know if my math and thinking is on the right path. Getting exact dead on measurements comes when I go to pick up whichever rear end I decide on, I just want to know if the way I'm using these measurments is correct.