IRS anyone?

[chevychase]

I just stumbled across this complete Mark VIII IRS and wanted some opinions on possibly throwing it under an 86 SWB with airbags. I believe it's 63" rotor to rotor (wheel mounting surface). I've seen they got an install kit for 73-87's here http://team321.com/truckirs/truckirs.html

As you can see in the pics, I have the entire assembly with the subframe. The IRS had factory airbags with an 8.8 aluminum center section, aluminum lower control arms, disc brakes and a rear sway bar.

I'd love to hear some input/opinions on this rear setup... good, bad or ugly












Underside Shot

[INSIDIOUS '86]

It's heavy. But in the right area. You cannot haul a load again. And the rear diff and axle I imagine are weaker
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[lo72]

I've been looking at the same swap. I think Porterbuilt has a kit for this swap. Trucks has a build on a ranger with type of rear end.
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[andrewmp6]

Porterbuilt has a c4 kit,Coming from a mark 8 owner pass on it and sell it.That irs is the weakest one ford made the cobra mustang is a copy but beefed up.

[Pop's C-10]

Go for it..it would be a cool swap..

[chevychase]

Thanks for all the input. I've seen a few trucks with an IRS browsing around so when I seen this cheap I just grabbed it for the heck of it.

[71swb4x4]

It doesn't look like you installed it right to me. I am pretty sure it goes the other way, and it's supposed to be under the bed.

[chevychase]

Originally Posted by 71swb4x4

It doesn't look like you installed it right to me. I am pretty sure it goes the other way, and it's supposed to be under the bed.

No wonder! hahaha

[Pro Performance]

Other than it being Ford parts.... I think it would be a cool idea.

[andrewmp6]

If you do go through with it get the diff cover brace and the solid front diff mounts that will toughen it up enough.

[canadian trucker]

There is a company in BC that is developing a bolt in IRS for our trucks.
I'll look for their contact info.

[chevychase]

Originally Posted by andrewmp6

If you do go through with it get the diff cover brace and the solid front diff mounts that will toughen it up enough.

Good point, I've seen those mentioned in my recent research.

[chevychase]

Originally Posted by canadian trucker

There is a company in BC that is developing a bolt in IRS for our trucks.
I'll look for their contact info.

Sounds cool... I'm here!

[chevyrestoguy]

Pretty interesting. I can see pros and cons with that set-up, but I see much more good than bad. It looks heavy, but if you spent some time eliminating the un-needed stuff, fully welding the seams on the framework, and sanding the excess flash and bumps off the lower control arms, it could look pretty cool. Question: I assume that this suspension uses an airbag from the factory? I don't see an area to mount a shock, but that's an easy fix.

The 8.8 rear differential is pretty tough, and there are vendors making nice aftermarkets parts for them.

You're going to have to decide what level you want to take the truck to. This set-up is going to cost more money in the end, and could compromise your ability to haul anything. It's also going to be hidden under the bed floor, and all that chassis work won't be visible. On the plus side, it should handle better, stop better, and if you install it up high in the chassis, the truck will be really low and have full suspension travel.

[chevychase]

Originally Posted by chevyrestoguy

Pretty interesting. I can see pros and cons with that set-up, but I see much more good than bad. It looks heavy, but if you spent some time eliminating the un-needed stuff, fully welding the seams on the framework, and sanding the excess flash and bumps off the lower control arms, it could look pretty cool. Question: I assume that this suspension uses an airbag from the factory? I don't see an area to mount a shock, but that's an easy fix.

The 8.8 rear differential is pretty tough, and there are vendors making nice aftermarkets parts for them.

You're going to have to decide what level you want to take the truck to. This set-up is going to cost more money in the end, and could compromise your ability to haul anything. It's also going to be hidden under the bed floor, and all that chassis work won't be visible. On the plus side, it should handle better, stop better, and if you install it up high in the chassis, the truck will be really low and have full suspension travel.

Yeah, I thought it would be pretty cool and probably handle nicely. If I did go through with it I would definitely lighten and clean it up and weld the seams/strenghten as you mentioned. This particular truck wouldn't be doing any hauling, just a street cruiser. And yes, the IRS did have factory airbags which I would use some sort of aftermarket bag and again some more fab work maybe even a cantilever system. I'm just kicking around ideas right now.

[andrewmp6]

Take a look at http://www.supercoupeperformance.com...px?category=79 they have all the upgradeable pieces

[chevychase]

Originally Posted by andrewmp6

Take a look at http://www.supercoupeperformance.com...px?category=79 they have all the upgradeable pieces

Hey thanks, I forgot about those guys! I had a T-Bird Super Coupe that would smoke my Vette!

[andrewmp6]

I love my mark 8 its almost a mustang cobra with a luxury car dropped over it.

[carcrafter22]

Get ready for plenty of wheel hop. I installed a 93 mark 8 IRS in my 67 F100 when and eventually sold the entire chassis due to terrible wheel hop, then again I guess a twin turbo diesel didn't help matters lol.