C4 corvette IRS in a '56

[cajundragger]

Looking for some info from those that know.

When setting up the center different, do I adjust it for pinion angle like pinion 3 degrees up?

or does it go level?

same thing with the motor...do I tilt it 3 degrees back as usual or set it in level?

Then about the rear end....

Im assuming ride height is with the LCA's parallel to the ground? correct?

I plan on using the stock spacing between the front bushings in the "trailing arms", but do I set the lower one level at ride height? or the upper? or split the difference?

and a general q...

how far down from height is it safe to go so I can calculate where I need to place the rear end to get the correct drop/ride height stance?

and just for the hell of it...how safe is it to go higher than ride height?


This isn't my first rodeo on a full frame but it is my first time with IRS and I couldnt find a decent book that had what I was looking for.

I know porterbuilt deff. knows these answers, but any help is appreciated, thanks guys.

[N2TRUX]

Anyone?

[abadsvt]

I have never installed a C4 IRS so someone else might chime in with some more help but from my knowledge yes the rear pinion angle will need to +3 degrees give or take just like a standard solid rear axle application. It uses a driveshaft so it should follow the same principles. Regarding where to located the IRS in a vertical plane I would like to assume that the center of the half shalft would be the same height as the center of the wheel. For example. My rear tires are 275/30/20 which gives me a 26.5" tire. Take the center of that at 13.25" and that is the height of the center of the half shafts. I would also imagine that the 4 link style rear linkage that holds the spindles would have the similar qualities to a standard 4 link so like if they are at an incline you would get more antisquat % that kind of thing.

Now I want to repeat this. My answeres are based souly on common sence. I don't not know if my answeres are correct but I would hope i am pretty close to the correct answere. Just thought if i though some of this out there someone else might chime in and clearify it better. Hope i helped!

Josh

[cajundragger]

Nathan from Porterbuilt gave me a call yesterday and helped me figure out all the specifics.

Im going to leave this thread pretty much unanswered until I can get a build thread going so I have pictures with my explanations.

Josh your pretty close to what needs to happen. I too assumed you treat it much like a standard rear end and thats basically correct.

thanks guys and especially Nathan from PB

-Dustin