pkwest

Be aware if you install delrin bushings in your IRS controll arms, they may get squeaky in time. Mine did only on the lower arms though even with grease fittings and were channeled. It was so annoying that I removed the lower arms and put a set of stock ones on for now. I have a machinist friend install spherical bearings in them. 1 contributing factor wheel hop is the forward bolts securing the irs cage to your frame. In some cars ford installed the wrong size bolt (they should be 14mm but in some ford used 12mm). It is also the cause of a clunk in some cars also.

SpectorV

a user on svtperformationce.com A427Cobra has a delrin kit that is much cheaper and much better than anything on the market currently.

Then use springs such as h&r race (good rate) with good shocks/struts valved to the rate of the spring

Get the heavy duty cross member race that the 99-01 cobra did not have, but 03/04 cobras and 00 cobra R's do.

Sticky tires will seal the deal

but do get an IRS brace like the one billetflow carries for security.