The 4.9 is more difficult then the 3.4 becuase you have to fab the exhaust. You could always pay someone to do this if you are not capable. The 3.4 can use the 2.8 fiero exhaust. There are several option of exhaust manifolds and routing. You can taylor it to your liking.
Engine mounts. You only need the center engine mount. Maybe fieroaddiction.com but more likely not. The only other place is WCF. The second side mount uses the 4.9 engine bracket, a poly or GM RWD trans mount, and a piece of angle iron welded or bolted to the cradle. Some also use a torque strut or some kind of brace for a 3rd mount. I have found no need so far on mine.
The 4.9 bolts right up to any fiero trans. You don't need to move the trans or anything to do with axels. This is how well it fits the engine bay. Flwheel needs to be made or bought. They run about 250 for a pre-made one. Or you can plug and re-drill the bolt holes to change to the 4.9 pattern. Use an 88 fiero or other neutrally balanced flywheel for this. Nothing real special there. The clutch is just a heavy duty fiero clutch. Nothing special there either. If you want to use the caddy 4 speed auto then you need mount brackets and axels.
Wiring is the most time consuming part. Its been throughly worked out though so all you really need to do is be able to read a wiring diagram and solder. There are always plenty of people to ask if you need help.
Fuel lines. These need to be either custom made or put together with adapters. Part numbers for the fittings are out there if you want a simple bolt on job. Its not cheap that way though. There are much cheaper ways in fact custom lines are usually about the same price. WAY less if you can do it yourself.
Coolant hoses. These need to be fitted. Not much to it. You can use a mixture of fiero and 4.9 hoses to do the job. You also need to figure on either an inline coolant filler or modified fiero filler neck. This will also determine if you are using a fiero or 4.9 t-stat.
Throttle cable. Use an 87-88 2.5 fiero cable. Works fine.
Starter. For clearance with a fiero manual trans you either have to use an Allante starter or trim the bellhousing for the 4.9 starter to fit. I recommend the Allante starter. Much easier and makes transmission changes easier in the future. Costs more though.
Belt routing. First eliminate the stock 4.9 steering pump/tensioner. This must be done since it interferes with the passenger side deck hinge bracket (you dont need a powersteering pump anyway). Then you can either modify the alternator bracket to create an adjustment or build a mounting bracket for a tensioner. The 3.4 camaro tensioner is usually used. Either way you also have to add an idler pully near the end of the waterpump.
Modify the Tach and add a speed signal circuit to make the tach and speedo function properly. This actually much easier then it sounds.
Oil cooler. Run one or not its your choice. All 4.9's had them from the factory but it has been proven several times that you don't actually need one for this swap.
That about covers it. These are also the basics for most any engine swap except the 3.4.
[This message has been edited by Fieroseverywhere (edited 04-16-2010).]