Dusterbd13-michael MegaDork
7/30/19 3:08 p.m.

So how much difference in the bores is there? 

SkinnyG UltraDork
7/30/19 3:43 p.m.

The Jeep is 71.6mm, whilst the Chevy is 78.3mm.

Also wanted to keep 14x1.5 wheel studs all the way around, but could not find any with a shoulder to match the holes in the 9" axles, so I ordered 1/2"-20 all around.

Also ordered an '87 Blazer gas tank, since I'm going to need to make the frame fit that.

SkinnyG UltraDork
8/2/19 6:17 p.m.

'87 Blazer tank won't fit a shortbed, so that went back.

Sandblasted the upper and lower control arms and cross shafts.

Machined out the 73-87 balljoint location and welded in a mounting ring for the 88-98 balljoint, offset to the outside 1/2" each side.

Sectioned the forward arm of the lower arms to make more room for the Fox-body steering rack.

Bought a gallon of Epoxy Primer.

SkinnyG UltraDork
8/3/19 2:17 a.m.

SkinnyG UltraDork
8/3/19 1:20 p.m.
pres589 (djronnebaum)
pres589 (djronnebaum) PowerDork
8/3/19 5:11 p.m.

Very cool.  Watched both the frame and engine videos.  Seems like a cool project and a ton of work.

SkinnyG UltraDork
8/3/19 7:29 p.m.

I usually bookend my projects with "...because I'm stupid...."

SkinnyG UltraDork
8/3/19 7:40 p.m.

Pie cut the upper arms, reducing the ball joint mounting angle by 10°. Should prevent locking up the balljoint should I decide to go air ride.

Gtholen New Reader
8/4/19 10:36 p.m.

I just subscribed to your YouTube Channel. I'll check out all your Apache Video's later. You seem to be making some great progress! Keep up the good work!

SkinnyG UltraDork
8/11/19 8:17 p.m.

Spent a week on Vancouver Island, which was good - I needed to figure out the rack placement.

I had to remove the driver's side eye mount, but I will replace that with a pipe clamp sort of arrangement.

SkinnyG UltraDork
8/12/19 8:37 p.m.

Upper arms, before and after:

And two coats of epoxy primer, and then 2K Chassis Black:

SkinnyG UltraDork
8/13/19 7:06 p.m.

I forgot to paint the lower arm u-bolts, but I still had some epoxy mixed up, and there was JUST enough left in the chassis black can to finish those today.

Also disassembled the front clip of the truck.  Only 1 bolt broke :)

Also got the ultrasonic pulse done on my elbows today, as well as the IMS and the electro shock stuff. My arms have been in pain since I pulled the blown 305 out of the Firefly last year. Physio says I have both Tennis Elbow as well as Golfer's Elbow.  I don't do either, but I sure can't swing a hammer anymore. It all started when I built a 50' Allen Block walkway and stairs up to my house 12 years ago.

java230 UltraDork
8/13/19 7:55 p.m.

In reply to SkinnyG :

Ugh I had golfers elbow. It sucks..... GL and take it easy on it. 

SkinnyG UltraDork
8/15/19 11:39 p.m.

Poly bushings and lower ball joints installed.  Still need to bolt in the new upper ball joints.  These are 88-98 ball joints in 73-87 arms, with lower ball joints moved outboard 1/2"

One bushing sleeve cocked and buckled, and after I finished swearing at it, I was able to remove the sleeve, unbuckle it, and re-shape it again and put it back together.

SkinnyG UltraDork
8/16/19 11:52 p.m.

Question to me on another forum, and I thought I'd share it here:

Why are you using 88-98 lower ball joints?

Good question. It's kind of a hodge-podge snowball of staying under budget and working with what I have and what I want.

1. I will be running a turbocharged LS, planning on 600-650hp to the wheels.

2. I'm not happy with the durability of the 12-bolt in my '77.

3. An 8.8 is narrower than I want, and I want to run the same size wheels front and back.

4. I've seen people on here using Jeep wheels in 18" and 20", but they need to use spacers. I like the look and the idea of those wheels, but I do not want to run spacers. I got a sweet deal on some 18" steelies.

5. I got a sweet deal on a 9" axle which I could narrow, but with the fwd-offset of the Jeep wheels, I don't need to - the wheels would be placed in approximately the same location as stock, which provides good clearance for turning while riding low (I have not decided if I want to air bag it or not).

6. The width of the 9" requires widening the front track quite a bit, which means relocating the ball joint location, or fabricating new upper and lower arms.

7. I got a sweet deal on a set of 2" 88-98 spindles, and since I need to relocate the ball joints anyway, I might as well make them work with the spindles. They are a bigger ball joint as well, and the 73-87 ball joints are not awesome. Plus, the 88-98 spindle seems to have more Steering Axis Inclination (SAI), which means I don't need to alter the upper control arm at all (saves work), and my calculations indicate I only needed to move the lower ball joint 1/2", which is (theoretically) a lot less than if I used 73-87 spindles.

NOTE: a larger SAI might have been employed by GM to reduce the scrub radius (the distance from the steering axis to the wheel centerline, at ground level). Ideally you want to be within 10% of the wheel width for scrub (in my case, 0.75" would be ideal). The 73-87 spindles have a fairly LARGE scrub radius, and my guess is GM tried to reduce it by increasing the SAI. A smarter way is to run more backspacing (FWD-style offset). The downside to a high SAI is you lose significant camber on turns (watch any MacStrut car). You then need a fairly high amount of caster to counteract that dynamic camber loss on turns. Lots of caster is almost always good, but can un-weight the inside rear wheel on a corner, resulting in wheelspin.

8. (I didn't plan this one) The 88-98 spindles mount the tierod below the steering arm (73-87 is above), which improves steering rack placement. Many kits that use the 73-87 spindles run a heim joint for a tie rod, mounted under the steering arm (easier to reduce/remove bumpsteer for sure). I don't want to run a heim joint, I want a proper tierod.

I think that's most of my train of thought. 

Make sense?

And honestly, I like "the build" and "creative solutions using OEM parts" and my labour is free.

wheelsmithy SuperDork
8/17/19 7:35 a.m.

Thanks for the schoolin'. I vote bags, but I don't have to do the work. 


SkinnyG UltraDork
8/17/19 5:40 p.m.

Spent a number of hours finalizing the Fox-Body steering rack to minimize bumpsteer. I had to take a small chunk out of the crossmember where the passenger side lug goes, but nothing I can't re-shape and repair.

I set everything up at ride height, and checked for any toe change at a full 3" bump and 3" droop, using this fancy device to see the change.

I got it down to a fart of toe in on both bump and droop, so I took the inner tie rods off and shaved 1/16" off the end of the rack threads, which now gives me a tick of toe out on bump and droop (dang!), which is more preferable than in (oh, well - yay! then). I guess I can shim it more precisely if it is even a perceptible problem.

Simple apparatus for adjusting rack height shown below. Square tube supporting Redi-Rod which is threaded into muffler clamp saddles (had to use zap-straps (zip-ties) to hold the rack, since I didn't have any 2.5" clamps). By threading the Redi-Rod up or down with a nut, I could position the rack, then test for bump steer.

Honestly, fretting over wee bits of bumpsteer is a waste, in my opinion.  If anything in the setup changes, nothing will be optimal and you have go in again.

I was, however, pleased to discover that full lock of the steering doesn't run the wheels on the control arms anywhere. Yay!

SkinnyG UltraDork
8/18/19 9:22 p.m.

Steering rack mount is done!

Passenger side was fairly straight forward, I made a 3/4" peg to hold the original lug of the Fox-body Mustang rack (mounting bolt not shown). The driver's side lug was machined off, the housing rounded, and a "clamp" mount to hold the rack to the crossmember. The mount took two attempts to make it work, and I'm mostly happy with it at the moment.....

SkinnyG UltraDork
8/19/19 9:31 p.m.

Uh oh.

The outer tierod is 11/16"-18 thread, an almost unicorn tap size.  I can't make the adapter sleeves until the tap comes in.

Guess I need to work on the house for the rest of the summer....

SkinnyG UltraDork
8/21/19 9:44 p.m.

Today I shampoo'd the carpets in the house.  Tomorrow I will clean the windows.

And..... I also ordered shocks, and an S10 Blazer gas tank with pickup and straps. Should be here next week.

Run_Away Dork
8/21/19 10:30 p.m.

You're moving quick! Do you have any deadlines planned?

SkinnyG UltraDork
8/21/19 11:35 p.m.

I wanted a rolling chassis by the end of the summer, I'm pretty much there.

Relocate shock mounts, mount the gas tank, mount the sway bars, fabricate the tie-rod adapters, and that's pretty much it. I want to spend winter mounting and plumbing the motor and trans and turbo and exhaust, then come spring start fixing rust.

Debating about picking up one of them cheap eBay air ride kits. I -do- have stock (will be cut) front coils as well as 5" drop rear coils.

SkinnyG UltraDork
8/24/19 7:17 p.m.

Turned out I was not measuring accurately enough, so I changed my tactic, went "oh crap!" and cut out the entire rack mounting, then tacked it up again with what I thought would work better. Ended up with 1/8" toe out on bump, and quite a bit of toe-in on rebound.

Then I second-guessed myself, and put it all back the way I had it before, and had a bit of toe IN on bump, but less toe IN on rebound. To fix this, I would have to narrow the steering rack, which I don't think I can do because it's a power rack, so I cut it out again and put it back to where I had changed it to, but a slightly different rack height, and now I have zero toe change from ride height to full bump (5" movement), but some fairly aggressive toe-in through rebound. I'm going to leave it and see. It's not a race car.

And, I installed the sway bar that came with the crossmember. Had to clamp a section of tube so I can get the jack out from under it.

Yes, that's sitting on the ground.

And this is why I pie-cut the upper a-arms. The angularity would have been way worse:

Also cut off the shock mounts, as I will need need to relocate or refabricate those.

Dusterbd13-michael MegaDork
8/24/19 7:24 p.m.

Laying FRAME.

Titanium drag blocks for all the dragging awesomeness?

SkinnyG UltraDork
8/24/19 7:28 p.m.

It likely won't lay full frame - I am not willing to sacrifice a useable bed.  I am willing to raise the bed floor 4", and the notches I put in are 4" tall, but frame just behind the cab where it kicks up will be 3-1/4" off the ground fully dropped. That's still plenty low.

The front crossmember I is intended to sit 5" off the ground.

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