Well, once again I dont have any pictures of my belt routing yet. My setup works pretty good. My setup is exactly like Mickey_Moose from PFF setup. Here is a link to his thread. That setup works great! I've had several people ask me what the belt tensioner and idler pully part numbers are so here you go. For the idler pully I used Dayco 89015 (NAPA 38008). It's a 70mm 6 groove pully. The tensioner is Dayco 305232. Dayco is sold at Autozone. All you have left to do is figure out your belt length after making the tensioner setup. I used a piece of string, routed it the way the belt will go, laid the string out and measured the length. Worked great!
The Cooling system is not too hard either. I ordered a Summit inline coolant filler neck which I ordered from summit. Part number SME-2202 at www.summitracing.com. This is spliced into the upper cooant hose about 6" from the thermostat housing. The upper hose that this splices into is the upper radiator hose that came from the Cadillac. This hose connects to the cooling pipe that runs uder the drivers side of the car. The passenger side cooling pipe connects to the hose on the back of the waterpump. The Heater core pipes hook up to the smaller pipes on the back of the water pump. In my car I'm still running the factory 4 cylinder radiator and didnt have any problems when I drove the car. The overheating problem I had in the begenning was because of an air bubble stuck in the system. After a good bleeding the cooling system worked great.
I decided I needed an oil cooler. I ordered a B&M transmission oil cooler. I mounted it on the front of the engine cradle and ran the lines up to the factory inlet/outlet at the oil filter adaptor. I have an oil temp gauge and noticed a huge difference in oil temp after adding this cooler. I would recomend doing something similar.
The wireing is pretty straight foreward. www.fieroaddiction.com has all the schematics for the Fiero C500 and c203 connectors and for the Cadillac 4.9L engine. He can also reprogram your chip to remove any unwanted items such as emmisions, auto transmission and passkey. You mount your PCM for the Cadillac in the same location as the factory Fiero PCM. You remove all the wires from the PCM that you are not going to use. Connect all your sensors following the schematic. I recomend useing the correct color wires in your harness to help you in future repairs. If you use the same color for every wire it will be a nightmare to repair wireing issues in the future. If you feel wireing is too difficut for you there are several people who will make you a harness. You can email Ed Parks at the Fiero factory (www.fierofactory.com) or PBJ on PFF. I did my own harness. I'm working on a couple of other harnesses for friends as well and have wired a couple of 3800SC swaps. I may be making wireing harnesses for people in the near future.
Note: You will need to use a 3 wire temp sensor from another GM Vehicle. This is because the Cadillac does not use a sender for a gauge. The 3 wire sensor uses 2 connections for signal to the PCM and the third is for the gague. This is how I got my gauge to work.
Note 2: You will need to have your factory Tachometer recalibrated to work with the V8. It will read about 500RPM high.