I'm 99% done with mine (damn O-ring cracked inside a P/S hose fitting during install so I have to pull it again to fix the leak) and it is technically a pretty simple swap. Here are a bunch of specifics to pass on from my experience so far:
1. The 4-bolt subframe must come from a donor vehicle that had the manual trans. If the donor car had an automatic transmission, the donor subframe will not work.
2. You can get the front roll resistor metal housing from the 2-bolt subframe to work. The studs need to be knocked out and the holes need to be elongated. The 4-bolt subframe uses a front roll resistor that has a wider hole spacing and instead of using studs, bolts are used and the nuts are already welded into the subframe. My preference is to get the roll resistor housing that was meant for use on the 4-bolt subframe. The reason is that if you are doing higher horsepower upgrades too, elongating the holes will weaken a 2-bolt roll resistor bracket. I've never heard of the bracket breaking but why take a chance when it is cheap to find one in a junkyard.
3. If you intend to keep the Stab-O-Shoc dampener, one of the two holes in the bracket that sandwiches between the front roll resistor housing and the subframe must be elongated (the hole that is closer to the Stab-O-Shoc).
4. Unless the large 12 mm bolts that hold the 2-bolt LCA into its corresponding subframe are corroded badly, you can reuse them on the 4-bolt LCAs as they are the same larger bolt used in that application. You will still have to acquire the smaller 10 mm bolts. These bolts can be acquired through Fastenal or Ford. It is cheaper to buy from Fastenal. Buy more than 4 because you will likely break 1 or 2 of them during tightening. The torque spec is 62 ft lbs for both the 12 mm and 10 mm bolts. I really think the 12 mm bolts should be tightened to at least 88 fl lbs like a lot of the rear suspension bolts are (all those are 12 mm bolts) but 62 ft lbs is really pushing the limit on a 10 mm bolt (2 broke on me at about 60 ft lbs). All the nuts can be purchased through Ford still but you can reuse old nuts as long as you add some thread locker. I did not like the nut offerings from Fastenal (shorter nuts with fewer threads to bear the load).
5. The bolts used to connect the steering column to the steering rack are one-time use bolts. The round-headed Torx bolt that connects that flexible flange to the steering rack is still available through Ford (buy 2 or 3 to be safe if you have to pull the subframe again). The bolt that connects the steering column to the flexible flange is also a one-time use bolt but Ford has discontinued it. It turns out that this is just a metric grade 10.9 bolt. I forget the exact diameter but I bought one that was 25 mm in length and after installing it, there was enough exposed length to had a reinforcing nut. The reinforcing nut is a good idea because the threads in the steering column like to strip out if the bolt is tightened and untightened too many times.
6. If you are thinking about getting the subframe powdercoated, you do not need a hydraulic press to get the bushings in and out; a hodgepodge tool can be built from some 1/2" threaded rod, some nuts, washers, 2.5" or 3" short plumbing fittings and a large socket to mimick the push-pull force of a hydraulic press. A breaker bar with a cheater extension will also be needed. The old bushings most likely are still good. Use only silicone oil to lube them when pulling them back into the frame. Surprisingly enough, all 4 new bushings are still available through Ford if needed (they were last Fall).
7. If you want LCAs that have a consistently good life expectancy, get Motorcraft. Don't buy Dorman!
8. The tie rod end nuts are considered one-time use nuts unless they are Cotter-pinned castle nuts.
9. The Teflon seal rings on the hose fittings where they go into the P/S rack are one-time use only. These can be acquired through Ford or Rock Auto and several other auto parts stores. Pay careful attention to torque on these as too loose or too tight will cause a leak.
10. As mentioned in the beginning, the P/S hose fittings have inner o-rings in them to seal the system. One of mine cracked during removal/reinstallation and I found out the hard way when refilling the system after installing everything completely. I could have found the leak just by adding fluid before installing the new subframe because the leak showed up immediately just from gravity feeding. There are two ways to fix the leak - replace the whole hose or replace just the fitting. Separate fittings (will have new teflon rings on them) are still available through Ford but it is very tricky to cut the old one off with a Dremel tool while avoiding damaging the underlying line. If the rest of the steel line is highly corroded from age, it is probably best to replace the whole line. Using a thread locking sealant may be a good idea but I have not tried this yet.
11. If you do this swap and you find it necessary to send out the P/S rack for servicing or replacement, it is absolutely imperative that you catch and save the check valve that goes in one of the ports where the hoses connect to the rack. Make sure you also remember the correct orientation and the port it came from. This check valve has been discontinued. When people get refurbished racks, no new check valve comes with them. If you lose the valve and install the unit without it, the steering system will lock-up. Many auto repair shops have gotten burned by making this mistake.
The SVT P/S rack is also different in that it uses different size plastic spacers that wrap around the rack gear. These spacers prevent the wheels from rubbing inside the wells. I don't know if you should be concerned about getting a different rack that has different spacers by accident as I don't know if a problem truly erupts from such a mistake.
12. There is a rubber bump stop by the right front subframe bushing that is used to anchor the steel P/S lines going to-and-from the P/S oil cooler. Check the condition and find a replacement if necessary. I don't know if these are still available through Ford.
13. If you have the radiator splash shield and intend to keep it, keep an eye on those plastic grommets at the front underside of the subframe. They are a rather hard plastic compared to a lot of other grommets. I haven't had anything go wrong with these but suspect they might be brittle so be careful if you have to swap any of these around. I don't know if they are still available through Ford.
14. If your lower radiator mount brackets/bushings are in crappy shape, new ones are readily available from Ford. The little plastic grommets that are in them for anchoring the radiator splash shield are still available; they are the same as the plastic grommets used to anchor the front and rear plastic wheel well liners to the frame of the car.
I have all the part numbers and links to the P/S hose fitting swap thread but don't have them on hand at the moment. There is another thread I started last Fall on this same topic; it will eventually be updated when everything is wrapped-up.
