Once more into the breach - narrower rear?

[70vert 17]

Hey all,

It's been covered here before, but inconclusively, and I'd like to get some educated guesses before I order my 9" from Currie. I just got my Evolution Motorsports 3-Link installed:

 

http://gallery.mac.com/jbauder?#100048&bgcolor=black&view=grid

 

and the handling is amazing. Tight ride without being jarring, the rear is far less vague and powering out of a corner it just plants and goes, and launching happens much faster with no spring windup to worry about.

Now I'm ready to do the rear and engine, rear first. I have a reasonable amount of clearance in the inner wheelhousing, none left at the fender. With the EvM kit, I'm not worried about body sway at all, the wheels will stay put in that wheelhousing. It's hard to get a good pic, but I've got some clearance inside there and want to go 1" shorter on either side. My wheels are 17x10, 5.5bs, 275/40 rubber. I could go 285 if this works later on.

Any final bets on whether I should go 1" shorter on either side? I won't hold you to it, and I could always use high-quality spacers if I goof, or just use the BFH on the inner wheelhouse. (even though I have a convertible, and can't massage it too much because the top drops down in there)

 

Thanks in advance . . .

[70vert 17]

(keywords: narrowed rear, shortened rear, shortened axle, shorter housing swap, etc)

 

I'd like to set up a place for people to post their narrowed rear housing info and their wheel size/backspace/tire info. Some of this can be extrapolated from other posts. (i.e., if your backspace is 5.5 on a 9" rim and your 275/40 tires rub inside on a stock axle, then the same holds true for a guy with a guy with the same setup but a 4.5"/9" rim backspace on an axle shortened 1" on either side.)

I'd still like to see it all in one thread on "narrowed rears" so we don't have to go around looking for the info in different places. I'm willing to be the first guinea pig! :stupid: Basically, the rear I'm ordering from Currie will end up being shortened 1" either side, for a 57.25 flange-to-flange width, or basically an early Ranchero width. Wheels 5.5bs, 9" rims, 275/40 rubber.

Brake drum/rotor thickness plays a tiny part, as well - according to Currie. .1" for drum to .3" for Baer.

Also mention if you had to massage inner wheelhouse or fender lip, of course . . .

Wish me luck! :clover:

[bnickel 10,004]

i see no problem with narrowing the rear an inch on either side as long as you have enough clearance

 

here's an idea, tape some 1" think foam to the inside of each tire and rotate the wheel around to make sure you enough clearance in each wheelwell.

[70vert 17]

bnickel, you're a genius! :detective: That's an excellent suggestion, I can glue in a foam block cut to 1" thick and contoured to fit the inner wheelhouse. I'd still have to drive it around and corner until the point where I lose rear traction. :biggrin: That would give me the point at which the body has pretty much rotated as much as it will rotate at the limit of traction. Then see if it rubs on the foam. Great solution!

[bnickel 10,004]

glad to help:biggrin:

[wantahertzdonut 10]

bnickel, you're a genius! :detective: That's an excellent suggestion, I can glue in a foam block cut to 1" thick and contoured to fit the inner wheelhouse. I'd still have to drive it around and corner until the point where I lose rear traction. :biggrin: That would give me the point at which the body has pretty much rotated as much as it will rotate at the limit of traction. Then see if it rubs on the foam. Great solution!

 

Just be sure to keep the shiny side up!

 

Out of curiosity, is there any reason you couldn't just use an axle made for a 67/68 car? I thought those were supposed to be 1" narrower. I've heard of guys using these on the larger cars to have a deeper dish rear wheel.

[bnickel 10,004]

Just be sure to keep the shiny side up!

 

Out of curiosity, is there any reason you couldn't just use an axle made for a 67/68 car? I thought those were supposed to be 1" narrower. I've heard of guys using these on the larger cars to have a deeper dish rear wheel.

 

 

actually the 67-68 rears are the same width as the 69/70, they just have a narrower wheel house

[cphsonic 11]

It's from 71 up they are wider. Picture complete! :tongue:

EvM looks sweet!. Did you end up leaving the exhaust like that or are you going for side exh?

[70vert 17]

Leaving it for now. It sounds and feels more badass than it is. I took my tuner buddy from work (who has a very nice Accord, respekt for his build and is working on a Lexus SC400) for a "before" and "after" ride with the 3-link, and he was really impressed with the "after". "it feels like the front and rear are connected now!" and "the rear slides much more predictably!" We had some fun.

 

Believe it or not, they claim they are working on a 2.5" kit over the whole shooting match, and I'm waiting to see how they accomplish THAT one.:dots:

[70vert 17]

ok, I bit the bullet and went with the Currie rear 1" narrowed on each side, so basically it is a '65-66 rear end at 57.25 flange to flange. I thought about doing the foam trick like bnickel mentioned, but I think it will be fine, and I can use a spacer if need be. Now before anybody poo-poohs spacers, guys like "bottle fed 70" on stangnet have been using them for years. AND I have beefy ARP racing studs from Steeda on the rear that are longer than stock so I should be AOK.

 

Bottom line - I would rather be too narrow within about 1" and be able to customize with a spacer than too long and not be able to do anything about it. We'll see if it allows me 285s or 295s. After I fry both rear tires when I do the stroker, that is. :whistling:

[70vert 17]

ETA update . . . Currie is out of the TrueTrac until August 1, so I'm waiting on that . . . decided on 3.25 gears since the stroker will do fine down low but won't rev quite like a shorter stroke engine. No need for anything in the high 3s or low 4s and I should get better mileage as a result . . .

[70vert 17]

ETA update . . . Currie is out of the TrueTrac until August 1, so I'm waiting on that . . . decided on 3.25 gears since the stroker will do fine down low but won't rev quite like a shorter stroke engine. No need for anything in the high 3s or low 4s and I should get better mileage as a result . . .

[70vert 17]

OK, here is the result - it is as tucked in there as it could be. Bump stop had to be ground down, inner fenderwells flattened slightly. With a wheel spacer, I could go to a wider tire. This is about as tight as it gets . . .

 

[bnickel 10,004]

looks good. you're gonna have to take that baby on power tour one year and swing by here and take me for a ride in it.....:shifty: