So I'm mid-process in converting a 2006 gto mp112 kit to fit my 2004. I would just like to share what I had to change in order to get it to work. I couldn't find a concentric thread that detailed everything so I decided to make my own. I will post pics when I get my hands on my g/f's camera haha.
Here's what I've done so far:
1). I needed to swap out the ls2 snout on the mp112 to an ls1 snout, I torqued the 4 bolts to 25 ft/lbs. It is necessary to use a metric crescent wrench on the 2 bottom bolts if you don't feel like taking the jack shaft and fuel rails off. The old snout will still be attached fairly well. So it is a good idea to put some towels or T shirts on the snout and tap it with a mallet to "gently" knock it off. (Don't forget a tb gasket)
2). The injectors, as far as I can tell, have ford ev1 to ev2 connector adapters for the ls2 injectors, to work on the ls1 all I had to do was pop them off with a flathead screwdriver.
3). The cable driven throttle body on a 2004 needs a bracket mounted to the side of the mp112 to hold the throttle cable. I torqued the 2 bolts to 25 ft/lbs. The bolts that fit were m8x1.25x12mm. I had to remove the jackshaft to get to these bolts :\
4). The valley plate is totally different on an ls1 gto, so I had to order a 2004 gto specific one from magnacharger. This plate has the mounts for the knock sensors and no vacuum line connector. *MAKE SURE you get the assembly instead of the just the plate. The assembly comes with the O rings and some very hard to find hex screws (lucky I got the assembly!). They are flathead torx screws, measurement is m8x1.25x25mm, there are 10 of them.
5). The metallic coolant crossover line between the heads was different. I had to order one from magnacharger. Not worth 200 bones imho, but what can ya do?
I will continue to add more and post pictures as I progress.