Hello everyone in the community. I have a few questions about suspension parts that I am trying to source out to hopefully make a kit to upgrade 70's trucks. So here is my story and hopefully a plan. 😁😁😁

My daughters and I are working on several 70's trucks and wanted to upgrade the suspension for several reasons. One is better ride. Two is better and cheaper wheel selection. And three for height adjustment.

The main reason for this project is to make a narrower suspension so we can use deeper dish wheels.

So we were looking at QA1 as a choice but the price can get high quickly and not to mention for a couple trucks. So, I thought why not make my own with parts anyone can get from the local auto parts store or junk yard as preferred. Some fabrication will be involved but if we can pull it off we could maybe spend no more than a couple of thousand with everything new or .maybe less if going with used parts. That would hopefully be for the whole suspension. qA1 looks good but this time I want to make a kit for us the DIYers...

So I was thinking of starting off with the crown vic components and using all I can except the crossmember . That is where the fabrications comes in. I'm not in it for the money. What ever comes from it if it works i will grandly pass the list to anyone interested and also measurements for making the crossmember.

So I think most parts are useable except the upper control arm and the rack and pinion. I have been trying to find dimensions on the upper control arm for a 2002 f150 4x4. I think if I can put all components on the 70's frame I will need a longer upper control arm than the one provided by the CV. I have also read that the mustang rack will work as well. I have also been researching the geometry part of it.

Another question, does anyone know why people say that longer control arms on lifted trucks give a rougher ride than stock?

Well hope to hear opinions soon or if someone has already done it then let me know. Thanks in advance.

 

I thought I posted about suspension upgrade a few days ago????😳😳😳

 

Welcome to FTE!

For some reason, some new posts get put in a waiting status. Anyway, I merged your posts and they are now visible.

 

I have never heard longer control arms hurt ride on lifted trucks. If anything the suspension geometry getting changed and/or the larger tires adding to the suspension's unsprung weight probably have a bigger affect on ride.

You may have trouble trying to get any modern system to fit under the truck with deeper dish rims since most modern vehicles used front wheel drive offset.

If you do not mind reduce load capacity a mustang ll suspension like street rods run would probably be the easiest way to get a narrow suspension. You could build you own suspension like a race car but there is a lot to learn in suspension geometry.

Good luck and keep up posted on whatever you decide.

 

This is an interesting project that I hope many folks here try to contribute to. Here is what occurs to me right away:

The CV IFS is a good solution except for the narrow range of wheel choice. There are vendors who offer shorter control arms to address this. This could be a shorter path: keep the crossmember and R&P steering and fabricate new control arms. Optionally, replace the spring with coilover shocks.

Alternatively, the Mustang II design is widely used and is well known. There are lots of vendors making what they describe as universal versions (see Summit for listings). No doubt these will require some adaptation but, again, the path may be shorter and possibly cheaper.

Then there is the Jaguar IFS.

 

About the longer upper control arms, I have seen that comment on almost every site that mentions going to longer upper control arms. So, I was curious since no one explains why.

As for the MII, for some reason it just looks a little on the weak side for a full size truck that I would like as a daily driver. Especially for the streets in Austin, TX. I have to take my vehicles for realignment at least once a year. I plan to enjoy it and not have it be a trailer queen or be in the garage all the time.

 

So after looking a little closer and also thinking about the coilovers, I might be able to use most of the CV parts except the R/P. Going to coilovers might also give me the option to get more clearance and closer to the frame if they are smaller in diameter than the originals on the CV. So far it looks like I might get about 1.25 to 1.5 inches closer to the frame. The next hurdle is figuring out if I can move the lower control arm that much inside. If all is possible I think the truck will get even lower by about another 2 inches trying to keep stock geometry. If all works out then I just need to fabricate the crossmember. Will need to figure out if I can go with square tubing and what size since it will be easy to make angle cuts and welds.

 

I forgot to mention the other CV IFS con and that has to do with matching the bolt pattern on the rear axle with the front so that whatever wheels you choose can be freely rotated. Related to that is the "opportunity" to convert to disks on the rear. This inevitably leads to the challenge of identifying the best JY option for 9" Ford disk brake equipped rear axles. Certain Explorer models appear to be favored. We need to keep the big picture in view.

 

That was another one of my reason to change suspension. I have a 78 short bed that cost me dearly to find 5 on 5.5 wheels. I literally paid twice as much or more for having this lug pattern as opposed to the 5 one 4 5. AND very very limited choices on styles.

 

As for the diff, I have been reading that explorers are good donors. I just went to the pick n pull and found several explorers with the 3.73 LS. I still need to verify if it is a direct fit and find out about the different sizes on the diff sides.

 

I am sorry, I do not have much to contribute, as I am not well versed in suspension, but if you happen to have 2wd trucks and are making a kit to make them a little higher, I would love to find out what you used if you find out a way. I would love the look of a higher ride. I have been putting off doing anything suspension in hopes someone can come up with a cheaper lift than auto fab. Good luck! I hope you can figure it out and I would appreciate an update when you get it going.

 

Hello Aggietrucks, I'm actually trying to the go the other direction but if I run across any info for lifting I will let you know. Just curious, how high are you wanting to go?

 

There's already narrow kits out there for about the price point you're shooting for.

NarrowCrownVic

If you're building from the ground up, you don't need longer upper control arms, those are used when you lower a stock vehicle to compensate for the extreme negative camber lowering produces. The longer arm will push the top of the knuckle back out to about a stock location. The problem is it doesn't compensate the extreme angle on the lower control arm so they won't run parallel and they'll travel through different arcs, creating odd wheel motions. The longer arms produce more motion..it's a longer lever and that's where the "rougher ride" feel comes from. It's mostly from using the longer arms without changing to a more compatible spring and shock rates.
When building from scratch you set your suspension up to the proper geometry and move the mounting points on the frame to compensate vehicle height.

Any major axle builder should be able to make you axles that will slide in your exiting rear axle and have the correct bolt pattern to match the front, then you just need to redrill the pattern in your drums/rotors. I'm assuming you have a 9"..I wouldn't swap that out for any other 5 bolt axle, the 8.8 is a good axle but at least with the 9" you can quickly and easily swap gear ratios and it has the biggest aftermarket support of any axle available.

The easiest way to do what you want is to cut out the frame rails where the suspension will mount and build new rails to mount the suspension at the track width and geometry you want. Then the hardest part will be finding an appropriate width steering rack. You'd probably be better off finding a steering rack that's close to what you want, then setting your track width based off that.

I know mustangs and CV's have very similar rack widths and ratios. I was thinking about swapping a Mustang rack into my DD CV, thinking it would have a sportier ratio, but after doing some research I realized there wasn't any performance to be gained.