I have an 89 Formula with a 9 bolt rear. I also have a 9" Ford rear, complete with disc brakes that is 5" more narrow than the 9 bolt. I want to drag race the car and I am considering a 4 link conversion to the 9" Ford. Has anyone converted to a 4 link rear suspension? My other option is to cut and weld 3rd gen axle brackets to the 9" so it will bolt in. I have 600HP NA right now, but will be upgrading to much more HP. I have the 9" already, so I may as well use it; I'm just wondering if 4 link would be better than the torque arm set up. All thoughts are welcome, and thank you for the help.

 

If you backhalf the car and Install a proper, fully adjustble 4 link, it would be a good drag setup. However is very labor intensive and can get expensive.

A Moser 9" bolt In housing and axle kit is about a grand, just add your center and whatever brakes you order it for.

Depends what you want to spend

 

I would like to have the 4 link, but you are right, it is a lot of work. I'm leaning toward modifying my Ford 9", and using Spohn coil overs. I can get a lot done with $1000.

 

Look into a Fays2 system. Good alternative without major modification.

 

Thanks for the reference. the Fays2 system looks heavy duty and good for road racing.

 

Go to www.autoweldchassis.com and see how they do it with there Ford 9 kit. I bought one years ago and I couldn't be any happier.

 

Thanks for the info, abray1. I took a quick look at autoweld 9" and from what I could see it looks good. I couldn't tell from the picture, but are there several mounting holes on the LCA brackets?

 

Once you go into back halfing the car you have a lot of other mods you will need. Full roll cage, padding on the roll cage, drive shaft loops front and rear, battery disconnect switch on outside of car, battery has to be relocated to rear in battery box, and tons more. I can get my car under 10 without back halting. I plan on staying above 10 to avoid all the expense on this car. If I decide to go faster it's time to start from scratch on another chassis.

 

Thanks to everyone who gave me input for this project. I have looked at many factors, including cost and I have decided to use the 9" Ford housing that I already have. My Formula is going to be a street driven drag car. I am going with ladder bars and coil overs for the suspension. I own a machine shop, so fabrication is no problem. The Ford housing that I have is already 5" more narrow than the current 9 bolt, so with mini tubs and the coil overs, I will be able to tuck some nice size meats under the fenders. One of these years, I want to race at Hot Rod Drag Week, and this would put my car into the "modified" category.