[jetdoc]

I have a 70 Chevelle 12 bolt differential with C lip eliminators, flange to flange measures the same as my 66 10 bolt 60 3/4 in. I measured my back space to the closes part that would contact my tire that was the frame just below the inner wheel house. My neg back space is 7 1/16 driver side, and 6 7/8 on the pass side...Looks like my body shifted a little! My question is I would like to narrow the 12 bolt 3 1/2 inches to make my wheel back space 2-3 inches, problem is I would be cutting into the shock portion of the lower control arm/shock mount bracket. I could relocate the shock mount by moving the lower portion inward by fabricating a plate behind the lower control arm bracket not a big problem yet my question is will the different angle bringing the lower shock mount inboard effect the geometry of the effectiveness of the shocks, I will probable have a to get a shorter shock, and should I fab up a angle bracket connecting the coil towers to move the upper shock mounting point inward the same amount as I do the lower to keep that geometry correct. Will there be any ill effect moving the assemble in 3 inches?

If this works I will have a like new pair of Strange axles for sale that I will post in the for sale section. Mark

[n20ta2]

Shouldnt hurt anything,I narrowed my 12 bolt 1.5 inches either side and just clipped the shock mounts edge.There are a ton of vehicles out there with shocks straight up with no ill effects,might want to consider eliminating the springs and shock mounts altogether though and run a coil over thats what I will do with mine.

[jetdoc]

n20ta2 Thanks for the input, 1.5 I believe would just not be enough I was hoping for at least 2-3 inches. Also I wonder how Coil overs would be compared to the stock coil/ shock setup as far as ride. Is there a coil over for the 66 GTO?

[n20ta2]

You can buy a whole kit with brackets from strange, Hal,ect for not to much money.Had 2 cars I did coil overs on and I liked the ride better then stock,the brand makes a difference as well as the valving and spring rates.Its also nice to be able to adjust the ride height of the car.

[n20ta2]

Also have moved the shock mounts in on a few customers cars over the years and hardly even noticed the difference in the ride quality.

[jetdoc]

Went to Strange and could not find a link for rears. Does anyone else make a rear setup?

[n20ta2]

they are universal kits,check summit or jegs they will come with the lower brackets to mount to your 12 bolt,shocks,and springs.you may need to fabricate a upper mont but its a piece of cake.

[hgerhardt]

Isn't it much easier to get different wheels?

[n20ta2]

I think he wants the deep dish look

[b-man]

The difference in shock angle after moving the lower shock mounting points inward the needed amount isn't an issue you need to worry about. The change in angle isn't very much, I doubt you'll notice any difference. Shorter shocks will not be required, the length change between the upper and lower mounting points is minimal.

I have a Ford 9" rear in my '64 GTO that has been narrowed 3-5/8" from the stock '64 dimensions, a stock '64 rear is already 1" narrower than your '70 Chevelle 12-bolt.

[gtome]

Is it very expensive to have a 12 bolt narrowed?

[b-man]

Originally Posted by gtome

Is it very expensive to have a 12 bolt narrowed?

Moser gets $125 for narrowing most housings and $110 to cut and respline a pair of axles, provided of course that the axles have enough 'meat' to be cut for new splines.

http://www.moserengineering.com/moser/shop-services/

So it looks like around $235 plus shipping to do it with stock axles, or add about $200 if you go for new stronger axles which may be necessary anyway.

[n20ta2]

125 is not a bad deal,I charge 200 but all my customers are local so its about the same if you had to pay shipping.

[jetdoc]

I got a quote of between 150-200 to narrow housing and 150 to re spline or shorten if there was extra spine length on my strange axles. I guess I am shorting the housing to use that wasted backspacing that Pontiac put into there setup, just seems like a lot of wasted room for available tire withe and better wheel selection. Just my .02cents.

[jetdoc]

Looks like I will go ahead with the narrowing of the housing, when I researched the rear coil overs I need the rear weight of a 66 GTO, anyone know about what it would weigh.

The thing I like about the coil over setup is I will be able to adjust rake angle and the ride characteristics with the shocks and not rely on the stock coil springs. Mark