Join Date: Sep 2006
Location: Las Vegas, Nevada
No there are no steering shaft issues with mark viii kooks headers they are the only header that doesn't require steering shaft relocation on the mn12/fn10 chassis. However as DLF already mentioned you may want to invest in a better rag joint assembly since the stock rubber one is likely high mileage and likely need replacing anyway as well as possibly being to close depending on manufacturing tolerances. DLF sells a kit for the MN12/FN10 chassis that's ready to go for a decent price.
Also be sure to order the right mark viii engine 97-98 or 93-96 headers since tbirds never came with secondary air injection and you'll need the right set. Bill will likely help you with that if you give him a call.
-1996 Pearl White Thunderbird 4.6 Sport 4v with many mods:
Current Best: 13.583 @ 103.74 10/2014.
227hp/241tq measured on calibrated mustang dyno, tested at full vehicle simulation with inertia enabled, no number skewing.
-2001 White Ford F-250 Super Duty 6.8 V10, 4-door, 4x4, Limo Tint, BFG KO2's, Bilstein 7100 Remote Reservoir Race Bypass Shocks, 6" Spring lift, Kenwood Double Din, K&N Intake, FlowMaster Exhaust
Amber_Murder's Daily Driver.
-2005 White GMC Sierra 3500 6.6 Duramax, Dually, 4-door, 4x4, Limo Tint, BFG Commercial T/A's, Rancho RS9000XL Shocks, Kenwood Double Din, K&N Intake, Banks Monster Exhaust
Chris_Murder's Daily Driver.