I'm pretty well complete mocking up the T Bird IRS in the 49 F1 except for the shock mounts but I just can't get a handle on how you select the proper shock length. When I searched I came up with lots of info on the strait axle but must have missed all the threads on the IRS. I understand how to find the measurment for a strait axle but I'm not sure how to find the travel measurments for the IRS. 4" of travel both up and down seem to be the magic number so if I'm set at the perferred ride height and it's 13 1\2" from the control arm shock mount to the center of the eye where I would fab the top mount then do I need a 10" shock when fully compressed that has 8" of travel or am I missing something? Perhaps some of you could throw out the type and numbers of what you have been using for this setup as examples? Once the mounts are welded in there's a few holes in the frame to patch and then the POR 15 can be applied. Sorry for the long post but this thing has been bugging me for quite a while and now it's time to deal with it. Thanks and look forward to hearing from some of you.
Remi

 

No help then??? OK

 

No idea, but I'll bump this for you.

Your post came in late on Sunday night, so maybe no one with an answer has read it yet.

 

Thanks. I think I have it figured out but would sure like to hear it from someone who has done it.

 

What I have always heard is to remove shocks and cylce the suspension. Measure the compressed length and then jack the frame and measure the extended length. Then look for a shock with a simalar compressed and extended length. The main thing is you do not want the shock to bottom out or be over extended. This is how they do it for lifted Jeeps, so I would think it would be the same for any other vehicle

Paul

 

I know that's how its done with the strait axle but is it the same with independant rear suspension. Here's what I get with the sway bar connected as it will be when finished. At rest, at ride height it is 14" from center of loop to loop. Fully extended - 16". Fully compressed - 12". This does not seem like alot of travel either way. If I understand this right then if I was to add a couple inches to the travel each way then find a shock with travel between 10" and 18" this would be the shock I need. Got it. Now if someone could post a brand and part number that could be used to cross reference different brands it would be a great help.

 

It seems to me that both Monroe and KYB have great info on their sites with measurements. I had them on my old computer but lost them when it crashed. Do a search.

 

I used the shocks off a 1972 Nova because I had a set when I fabricated the rear end. The ride height is at stock level and I have had no trouble . The bottom mount is in the original position on the 1995 T-bird IRS and used the original bolts to mount the bottom. You can see the top mount I fabricated from angle iron.

 

This one is extended all the way out.

 

Once again you've come through for me on this build. The local NAPA dealer said if I could give him something to cross reference we would have a starting block. Now I got that block and can move forward. Thanks, and I do mean it. I used your idea on the front subframe mounts and am very happy with the results. A few odds and ends left and I can spin it around and get started on the jag ifs. Thanks again. Did you use POR15 on your rear end?

 

I sansblasted the entire frame and sprayed it with rustoleum primer and painted it with satin black tractor paint from Tractor Supply.

 

I also believe Bilstein has shock lengths on their web site.

Paul