can anyone tell me what head people use when they fit twin cam heads on 2.6l motors and what involved chain/belt wise thanks

never heard of a twin cam fitted to a 2.6 .
some people have fitted vr4 motor,s to gen1s

There was a twin cam head made for 4G54 but only one is knowing to survive. So your out of luck, sigma-gallant forum has a good information about the 2.6L 4G54 motor. If you want a double over cam motors been told other Mitsubishi engine will fit into the space :)

If any one has the specs and dimensions of the twin cam head i would like to get my hands on them

Apparently I was told a volvo twin cam motor head might be able to made to fit a 4G54. I only seen photo no specs of the twin cam head.

AFAIK its the 2.4l block found in some 3rd gen magnas that the Evo boys use to bolt their 4G63s onto.

http://www.dsmtuners.com/forums/152036328-post6.html
OK, Im doing the swap right now, but I needed more parts to convert my ignition from distributor to coil packs, but you guys with the spyders already have that, so it will be a P'n'P for you.

Parts that you need:

DOHC head /obviously/ + MAnifold and Fuel rail
You could reuse the stock TB, but if you decide to upgrade to 1g TB youll need to swap the ISC
94 Galant Cam Gears /stock 4g63 wont work, you need ones off 4g64 DOHC/
94 Galant 4g64 DOHC Timing belt /stock 4g63 comes a bit short/
94 Galant 4g64 DOHC Head Gasket
1x1/2 inch freeze plug; 2x5/8's freeze plugs and 2x11/16's freeze plugs /you need to plug these on the block, because the DOHC head does not have the oil drain passages/
2g CAS to swap with you spyder CAS
1g or 2g Thermostat housing /4g64 feeds the heater and TB coolant straight from the head/
2g water pipe /4g64 water pipe ends in the 4g64 thermostat, with the new thermostat housing you need to reroute that, plus some peops already have turbos, so the coolant can drain in the new water pipe/
2g radiator hoses

http://extremeevolutions.com/4G64_buildup.htm