20" rim on front. 22" on rear. 120.65 to 120 comparison. '86gp

[libeachboy]

today i odered the parts for one front wheel for fitment. my thanks go out to nick @ tires by web on ebay
who spent time with me and researched my options in his catalogs.
i'm going with 20"x8.5" with a 5x120 bolt pattern on a hubcentric ring - 70.3mm/car to 74.1mm/new rim hub bore.
offset is 18mm and - the most important number to me - backspace is 5.5" (nice sounding number). i'm using hoffman 'on-car' balancing.
i'll have the parts soon and will post photos of the fitment. i'm also almost done figuring out the rear.
i made the graphic'ed photo above my desktop background - i'm obsessed!

 

[libeachboy]

today i ordered one rear rim for fitment.
22"x9.5" with a 5x127 bolt pattern. backspace is 5.96". offset is 18.
i am using 120.65 to 127 adapter/spacer at 1.5" thickness on a hubcentric ring 70.3mm
to 74.1mm. if fedx comes on time i'll be working on my rims - front and rear - next weekend
and will post with photos. the new tires will have to wait until the spring.
that will be it for any car work this year. it's snowed just north of us. .... time to cover up.

 

[libeachboy]

these are photos of the actual measurements i made. numbers alone can be confusing. because i started with larger wheels i kind of had a blueprint.
- the car is jacked up and the old wheels are coming off.
- the old rims are measured for backspace. 4" in the front and 4.75" in the rear.
- the specs for the new rims are measured. 20" rim with 10" diameter. measured behind the
hub and in front of the hub.
- the new rims backspace of 5.5" is measured at the tie rod end, the upper control arm and
stabilizer. everything seems clear.

 

[libeachboy]

here's a look at the rear.
my position is lying down and looking back at the wheel from the rear. i look to my left at the inside of the wheel and without changing my position look to my right at a view up at the outside tire clearance at the inside fender well.
- inside backspace. this shot is just above the exhaust tip to the frame and my fingertip. my fingeritp
is about 1/4" thick wedged in there. this shot is with my present 4.75" backspace at driving height. you can see 4.5" is the correct number. the new rim has a backspace of 5.96. i'm using a 1.5" adapter/spacer going from 120.65 to 127 on a hubcentric ring. the math: 5.96 minus 1.5 is 4.46. my new wheel will sit at 4.46" backspace to start my fitment. the tire at my fingertip is a caliper measured 10.25"
- the outside wall of the tire and the inside of the fender well are about 1" apart. maybe 1 1/4".
- a view from directly at rear and under exhaust tip. that's 10" of rubber.
- the complete wheel at driving height. as ungn mentioned in an earlier post ..... 'a 255 is a big tire'.

my new rim is 9.5" wide. it looks like it's going to be close without a small mod to the fender lip to get them in there.
not so much the rim but the tire i think. but it's possible. if i can keep a 10" wide tire it should be a go.
i'm studying the tire sizes crucial118 gave me in an earlier post.... interesting numbers and good photos of them on his car. .... but i think i want a little more sidewall. the wheel well has room for height.

 

[UNGN]

How wide is the wheel shown? 8"?

The Perfect back spacing for a 9.5" wheel without a frame notch would be 4.75" 4.5" should work with a fender roll. I bought one of the Eastwood knockoffs off Ebay for $100 and a $9 Harbor Freight Heat gun. Have already rolled 4 of my cars with it.

 

[565bbchevy]

Just so you know Eastwood has their fender roller on sale right now for $60
http://www.eastwood.com/ew-fender-r...2OTGHFDovdSxWUwISC8IzyVyGFWG43rhDIhoCqi7w_wcB

 

[libeachboy]

thank you ungn. the tire is a 255x50 @ a measured 10" wide in the photo. backspacing is 4.75".
i'll be fitting the new rims this weekend.
thank you 565bbchevy. great link to the eastwood roller. it will be handy up front.
but i don't know how to use it in the rear without jacking up the entire back of the car and dropping the driveshaft. and even then ....
the rear is a 1987 gmc suburban hd 10 bolt 8.5" - 3.73 posi truck rear, carrier axles and all. i don't think it's going to
turn for that roller.
at any rate the first thing is fitting the rim and that happens this weekend.

 

[libeachboy]

i received my hubcentric rings and the front rim. fast deliveries. i've read a lot of people have issues with some of the things i'm going to do. here is my experience with photos.

- i'm going from 120.65mm/4.750" gbody lug pattern on my car to 120mm/4.724" on my new rim. some say you can and some say you can't and both sides seem pretty vocal.
- first: i fitted the hubcentric ring over the front hub on the car and it fit perfectly. 70.3mm
- next: the photos show that the rims come pre-machined by the manufacturer for the rings. with the ring in the wheel, 74.1mm, it will now fit perfectly centered on my front hub.
- and if you look at the rough measurement of the lug pattern you can see what looks like 4.75" between lug holes. it looks really close.

 

[libeachboy]

here's the front wheel so far. i need to get lugs.
everything is nice. better then the old wheel setuo so far.
just beautiful. (the photo does not show drive height at top
but the botton is the height of a 2.5" sidewall)
i'm starting the back now. it's so big. omg.

 

[libeachboy]

120.65 comparison to 120. you decide. shots of each individual lug.

- i got standard lugs to test with. 3/4 - 19mm hex, 12x1.50 .... old style.
- measure in new rim lug recess.
- holding the new lug in lug recess.
- view of entire hub.
- view of lug #1
- view of lug #2
- view of lug #3
- view of lug #4
- view of lug #5
- getting ready for rear wheel.

i don't know what the fuss is about. this rim with a hubcentric ring and conical, no bulge lugs fits perfectly. no fear.