Centering MII Frontend

[whitedog76]

Ok, I received my MII crossmember the other day. Now the hard part starts.

Most all of the MII kits out there state to install the crossmember 18 1/8" centered from shackle mount.

The factory assembly manual states 18.28" (let's call it 18 1/4).

When dropping a string line, I'm at 18" to center on my solid axle. Of course, that's with 60+ year old leaf springs. If you look at a picture of my truck. (It's not a good one, but the only one I have with the factory sheet metal in place.) The front axle is a little far forward in my opinion.

I'd like to run around 5 degrees of castor. The instructions on the top hat say to install it at 1 3/4 forward of the crossmember. So, my way of thinking is to install the crossmember at 18" and shift the hats back a little bit. From doing some math, there needs to be 3/4-1" difference in the centerline of the spindle in order to get my 5 degrees.

Am I on the right track or am I over thinking it?

[whitedog76]

https://static.speedwaymotors.com/pd...7%20Heidts.pdf

[whitedog76]

My next thought is to just square the upper hat with the lower crossmember, like what you see here with the TCI kit.

They have an upright bracket that compensates for anti-dive and is adjusted with shims, not T bolts.

[mr48chev]

On the amount from the center of the front shackle bolt hole to center of the axle some prefer to adjust the centerline a tad to get the wheel centered exactly where they think it looks best in the wheel well. That is a personal choice thing. Go to an event with 50 AD trucks with crossmembers installed in the and you probably can take photos with minute differences in exactly where the front tires sit in the wheel wells on a third of them.

On the hat's location as compared to the crossmember and lower control arm I'd have to say to with what that unit's manufacture showed in the assembly manual and don't try off the wall relocating or you throw the built in caster off. Every set of instructions I have seen have the hat offset to the rear about that same amount.

[dsraven]

chat with the TCI guys and see what they say and why. try to get a drawing from them for your style of truck. get the alignment specs at the same time

get the frame level side to side, square and at rake angle you like, then block it securely. mark the new axle centerline on the frame with a light punch mark so you can drop a plumb line during mock up. sometimes it helps to have a long straight piece of bar/tubing or whatever that you can clamp to the frame so the plumb line is easy to check by yourself. of course having 2 plumb bobs is nice as well but not required

install the cross member with the lower control arm pivot shafts level to the ground from the front (side to side) and from the side. use the level on the shafts not the top or bottom surface of the cross member because it may not be perfectly straight with the shafts. ensure the new member is in the center line of the frame as well. use a stringline or laser to get all the cross members lined up from the front to the rear (mark center on each one then string/laser down the middle front to rear. don't lie to yourself if the frame is bent or you will likely be spending more money later)

[dsraven]

I think, in the pic of the green truck, the front wheels are slightly turned to the right. that may make the wheels look slightly further ahead of the axle center line.
another hint is to also lightly punch the original front spring pin center line on the frame, once the frame is in position. that way you are not guessing every time as to where the center is.

[whitedog76]

I was just looking at a post from another member. I really like their TCI chassis. Mine came from CPP, which I believe is made by Heidts.

I'm just trying to figure out how to make mine better, without muddying up the water too much.

The spirit of hot rodding is doing something different from the rest.

On a second thought... Who needs instructions? LOL

[whitedog76]

what about using a bushing to help fine tune things?

[mr48chev]

What exactly would you be fine tuning with that bushing? You lost me somewhere with this. I did front end work and alignment for a living for a number of years and if the the builder of the crossmember has it designed right their design should function correctly. Making changes just to make changes without a sound knowledge of the why you are making a change is rather foolish.

The only viable reason I can see making mods to the setup are if you are building it to use in competition such as the Goodguys autocross and it is a dedicated use vehicle.

[whitedog76]

Just over-thinking things. I have a tendency to look at things outside the box.

I believe my best bet is to install as intended. I do like the TCI upper hats for adjustability, guess I should’ve bought them instead. LOL.

Keep It Simple, Stupid!!!

[Fiftee3]

Hello W/Dog,
So here's my 2 cents. Yes, all seem to want that measurement from shackle mount. I used JW Rod Garage MII. There directions stated 18 13/16 from rear spring mount. So I followed the instructions. Also, and this is IMPORTANT, I scribed a line deep into my frame on both side where original I beam sat, just to see where new cross member would sit.
Now I did not put my fenders on before fully welding, which IS recommended.
Too heavy!. All said and done, my wheels are a little far forward, however, tires and turning clear, and overall, looks great and more important, drives great!
Main thing, You want to be sure your lower control arms are level, or close to at ride height. You will also have to cut inside fender liners a few inches to clear A-arms. I also saw your post on front brakes. Mine uses 78-86 metric F and G body rotors, Ford Granada rotors. With the Ford (' out back and 11" drums, stops like crazy. Remember, your not driving a new 2018 Camaro here.
I would not want to widen your front stance as in your other post. May affect what wheels you use.
As for the way the hats mount or adjust. I too have the t bolts on top hat. While I would do it differently next time, They have never loosened up yet!
Best of luck with your build!

[whitedog76]

I’ve had time to think about what it is I’m wanting to do. I was all over the place before. (It must’ve been a 2 pot of coffee day.). The lower control arm and upper hat, need to be square with each other, no matter what. So, shifting things around, really gains nothing. Centering the crossmember at 18 1/8 is actually adding a little castor, right off the bat.

In hind-sight, I think I should’ve bought a TCI kit, or at least buy a set of their upper mounts. I like the idea of being able to adjust caster and camber independently, instead of cranking the upper arm at an angle.

As far as the brakes go, I had some parts left from when I was working on converting the 8 lug axle to discs. The folks over at Scarebird actually use Ranger hubs/rotors on a number of their conversion kits. I got to thinking, why not go big?


It’s kind of funny, I was actually thinking of mounting the crossmember similar to way you did with the rear bracket. I don’t really like how the rear of the lower arm is just hanging out there.

Anyway, thanks for the comments & suggestions.

Chris