Rear suspension questions for the experienced!

[3100 special]

First, I'm mechanically inclined but, not a mechanic. I can figure out most things by looking how they are assembled but let’s face it, there’s no way to replace the experience that some of you have in the field. Ask me anything about communications equipment or data networking, I’ve got an answer. But suspensions….?!

I’m looking at removing the stock rear out of the 54. I’m leaning towards a Ford 9 inch with disk brakes. The questions:
• What years/ makes are good for the weight of the panel? (without ABS). 1994 Thunderbird?
• What are the advantages/disadvantages to going with a 4 link suspension?

I plan on using the panel mainly for sporting around on the weekends, occasional road trips. I definitely need a rear end that will handle some power as I up the HP on the engine (I plan on starting with around 350-400 HP) and I don’t want to have to go back and start tooling with the rear to handle it. Saying this, what is the average gear ration that will be in the stock rears that you recommend and what does it need to be?

Thanks!

[Tx Firefighter]

94 Thunderbird will be an 8.8 rear end. It's a good one, but not quite as strong as a nine incher is.

I'd slap a rearend into your truck and keep the rear leaf spring type of suspension. There are several ways to get it to set at whatever height you desire and it will be much cheaper than going to a 4 link.

[crazy longhorn]

Nice panel! from the pics, i am guessing that you still have the 6 lug hubs? if you plan on keeping the straight axle, & the alum wheels with the truck, you might opt for a 6 lug truck rear diff (12 bolt). 67-69 were a tad narrower, than the later ones, & that 12 bolt truck diff will easily handle 350-400 hp. I also agree with TX Firefighter.....keep the leaf springs (they cant be too outdated, if they still use them on the '04 trucks ) I run leafs on my longhorn, & dont have any issues with them. Best of luck....crazyL

[TheFabShop]

You can get them out of any older ford trucks and most bronco's.This is a real good rearend to build and cheap I might add.I would go with a 355 gear depending on tranny.

[68LSS1]

Here is a couple pages of data on 9" rears:1, 2 and 3. hard to say on the ratio without knowing what type of tranny you'll be using. Since it will be a weekend driven vehicle I go with a 3.25/3.50 with a auto, 3.89 with a 5 speed and 4.11 with a 6 speed for starting points. Those are 9" stock ratios. A 8.8 will probably be easier to find and hold up well to 8 second and faster Mustangs. The Mustangs are light so you will have to watch the torque you put to them but they will handle a good amount. I'm using a 8.8 out of a late model Explorer with a 3.73 traction lock and disc's. I'm getting rid of the C clips (as they are not NHRA legal anyway) and you can get pinion yokes for 1350 u-joints (the 8.8's you're likely to find will have a round flange where the drive shaft flange bolts to this one). Width will definitely be a issue and I can measure my 8.8 and let you know if you want.
As far a a 4 link it's biggest advantage is adjust-ability. Biggest con would be price for some or the fabrication for others. If you can do the fabrication your self they are pretty cheap. Leaf springs will hold up to 400hp no problem and maybe you can if you can get a set of CalTracs. The 4 link is a better suspension but it will be up to you to decide if it's necessary for your application and goals for the truck.

[3100 special]

Tx Firefighter: That is an 8.8. isn't it? Told you I didn't know much in this area! The cost of the 4 bar is a bit. Roughly 500 for the plain and 800 for the stainless (Heidt's). The only thought on going to it was to get more energy to the ground. I guess that could also be accomplished with traction bars, if needed.

crazy longhorn: Thanks! When I saw it years ago, I knew that it would be a cool rod one day. It is still a 6 bolt. Back when I bought it I was driving it to work. I went out and bought those Center Lines for about 75 a piece, new. I really like the way they look but I not going to let them control what I put in the rear. If I can get them to work, great. If not, I'll sell or trade them and get new...something...maybe the same (if they still sell them) or something else. The truck has an enclosed drive staff connected (riveted) to the axle. It's all going away. I had strongly considered a Chevy 12 bolt. I really don't know what would be the best. I'm looking for the least amount of modifacation work and the best performance on the street.

TheFabShop: Cheap is good! I was looking towards the TH-700R4 for a tranny. On this item, I wasn't going to try to get something from salvage. I intended on getting a new one. It'll cost but, Ifigured when it comes to the engine and transmission, I'd be better at going with a "known good". I'm not dead set on the TH-700R4 but, it seems like it would be a good unit...properly geared.

68LSS1: Looks like I'll be doing some reading tonight. Thanks for the resources! I was reading last night on some of the shifters available. If they work light they are described, I'm looking at the shifters (like B&M or Hurst) that are automatic but can be dropped into low for manual shifting. I'll have to look harder to see how many gears these units handle. I just started reading on that topic so, lot to learn there as well.


Thanks guys!

[3100 special]

68LSS1:
Excellent information on those web pages.
Thanks!

[longhorn71]

Originally Posted by 3100 special

First, I'm mechanically inclined but, not a mechanic. I can figure out most things by looking how they are assembled but let’s face it, there’s no way to replace the experience that some of you have in the field. Ask me anything about communications equipment or data networking, I’ve got an answer. But suspensions….?!

I’m looking at removing the stock rear out of the 54. I’m leaning towards a Ford 9 inch with disk brakes. The questions:
• What years/ makes are good for the weight of the panel? (without ABS). 1994 Thunderbird?
• What are the advantages/disadvantages to going with a 4 link suspension?

I plan on using the panel mainly for sporting around on the weekends, occasional road trips. I definitely need a rear end that will handle some power as I up the HP on the engine (I plan on starting with around 350-400 HP) and I don’t want to have to go back and start tooling with the rear to handle it. Saying this, what is the average gear ration that will be in the stock rears that you recommend and what does it need to be?

Thanks!

Just a thought.If you found a late70s-early 80s caddy seville rear end.they are roughly the same width and have rear disc brakes on them.their bolt pattern is 5 on 5.5.the best thing about these rearend are the are a bolt in swap i have heard.Not as strong as the nine incher though.

[crazy longhorn]

Originally Posted by longhorn71

Just a thought.If you found a late70s-early 80s caddy seville rear end.they are roughly the same width and have rear disc brakes on them.their bolt pattern is 5 on 5.5.the best thing about these rearend are the are a bolt in swap i have heard.Not as strong as the nine incher though.

Those Caddy's are a 5 on 5 pattern....crazyL

[longhorn71]

oops i thought so