You'd have to change:
- Muffler inlet flange to a GT 4 bolt, or just weld a 3" v-band on it and be done with it. A V-band interface will allow quicker/easier removing of the muffler, instead of stuffing around trying to access rear bolts etc.
- Oil drain flange on the GT is different to the KKK
- GT turbo has a 2.5" outlet on the compressor side, so you *may* need a reducer if your KKK has a 2" outlet.
- GT turbo has a 4" inlet to compressor, but you can get the supplier to CNC it down to a 3"-3.25" to make it easier to mate with your existing air intake pipe depending on what size it is currently. You may need a silicone reducer there too.
- oil feed line for GT only needs a -4AN, otherwise you'll over-flood it with the existing oil feed line I'd say.
Hope that helps.
'89 911 Turbo Cab
Protomotive MAP ECU, Twin Plugged Heads, GT2-EVO CAMs, 3.3L fully finned P&C's, ARP fasteners, C2T head gaskets, Titanium Retainers, Turbo spec valves, springs & guides, 964 splash valves, GT35R BB turbo, GSF Stainless Headers, Magnaflow Exhaust, Full bay Intercooler, TiAL 46mm w/gate, TiAL 50mm BOV, Apexi AVC-R EBC, SPEC Stage3+ Clutch kit, Crane CDI Ignition