Numbchux

Anything is possible. Rear diff is almost certainly a different ratio, so that'll have to be swapped as well. Not ideal ratios for non-turbo and tall tires. ASSuming the Forester is already a 5-speed. It will likely be a pull-style clutch, where the WRX will be push-style. They should both be hydraulic, so you'll just use the WRX flywheel/clutch/slave cylinder. I *think* a 99 aussie car will be phase 2, 8 bolt bellhousing. It's possible it's a phase 1, with 4-bolt bellhousing, in which case you'll be missing the lower starter bolt. There are about 6 ways to deal with this, documented thousands of times on the internet.

1996 is OBD II. Plug in a scan tool and see what's wrong. Then test the circuit and repair.

Nope, phase 2 revision 2 started in 2004.

It happened, I got some time for a project! They're both top feed injectors, but the 2.5 one is different, using a different O-ring and a retaining clip to the rail, and with an extra section on the end for the Air Injection system. 2021-10-18_10-01-19 by Numbchux, on Flickr I put it back together as it was, but it leaks, so it'll have to come apart, again. I've seen people talking about using WRX top feed injectors when turbocharging an EJ251, but they generally block off the air injection system. I'd rather leave things as stock as possible.....but might have to experiment. I think it's either modify until the 2.0 injectors work. Adjustable pressure regulator to drop the fuel pressure. Or have a trouble code.

I just remembered the other thing I did. I hooked up a battery and used the starter. It can apply way more torque to the rotating assembly than you can on the crank bolt.

I loosened the case half bolts a couple turns, and smacked the crank snout side to side with a mallet a few times, and was able to get mine to turn over enough to get to all the converter bolts.

Only way to get 100% OEM, is buy OEM. You can buy a part directly from an OEM supplier, but it's not guaranteed to be the same quality as an OEM part.

Yep, in fact, the name on the package is almost never the manufacturer of the contents, especially when it comes to brick and mortar parts stores. IMHO, there's only one thing that definitively separates the various aftermarket parts, and that is the warranty, which is handled from the retailer (getting a warranty replacement from RockAuto involves paying round-trip shipping, for example). Something else we see, is an OE supplier (Denso, Mitsuboshi, Johnson Controls, etc.) will likely have different quality control requirements when they supply for an OEM then when they sell through another retailer. So even seeing a brand name stamped on a part doesn't mean the same quality part.

Aftermarket Subaru head gaskets = higher failure rate. Absolutely. You can use aftermarket if you like on the rest of the gaskets. 770 is the end of the Subaru part number for the STi application. This is an MLS gasket that will give the best results. If you don't want to do it again, use these. Should be EJ253, tag on the LH strut tower will tell you. Subaru head bolts can absolutely be reused if they're not damaged/corroded, in which case, replace them individually with OEM.

I always buy AutoZone pads, for the warranty. I've used a couple sets of the Duralast Gold rotors, which have a zinc-based coating. I found that to flake off very easily (it's designed to, as they coat the entire rotor and let the pads wear the coating off on the friction surface). Many of the standard Duralast rotors have a coating on them, now. I haven't tried them, but might be worth it. We buy a lot of O'reilly's Brake Best Select rotors at work, those have what looks like a nice coating on them. Just had a set installed on my mom's 2012 Impreza....I guess time will tell how they hold up. I bought a set of Durago coated rotors online several years ago for our Outback. I found that they left too much metal exposed for the friction surface, and I immediately began to get a ring of rust there, which crept under the coating. Aftermarket rotor prices seem to have doubled in the last couple years. Price out OE rotors for your application. They will be more, but they might be competitive, and they will be better.

Not the first person to report a failed Gates belt with no warning or other sign of wear/failure. Your junkyard motor is trash, take it back, or take it in for scrap. Take your old head to a machine shop for new valves, seals and a pressure test.

"Should" go in. Experiment with the axle shaft into the inner joint. Occasionally those get pulled apart, and won't line back up correctly.

There's a "read mode" wire at the ECU. Ground that, and it will flash trouble codes on the check engine light (can be done with a test light at the ECU, as well).

Pinion seal is kind of annoying to change, as the nut has a lot of torque on it, so holding it solid while removing requires a fixture of some sort. And, has to be retorqued precisely. I replaced one once with none of the right tools (I think I torqued it with it in the car and the back wheels on ramps), and the diff was noisy forever more after that. That should be either a 4.111 or 4.444 gear ratio. These are stupid common, and pinion oil leaks are rare. You can likely get a used diff for cheap. I've had 4 out in the last year, without too many dramas ('98 Forester, '01 Forester, '97 Impreza that had had the strut tower fail due to rust, and '00 Outback that I was worried about subframe failure, these were all MN cars). The '97 Impreza, I had to pound 1mm undersized sockets onto a couple of the factory bolts to get them to come out, but wasn't too bad a job. Or....you'd be surprised how little oil can leak and leave quite a smear on the outside of the diff. Check the fluid level periodically, and keep driving it. Assuming, of course, you mount your fuel tank somehow, I have not had to deal with failed tank straps, yet.

You might contact these guys. Probably the shop that did the most with the EE20s in the US. They were importing and selling them for a few years, but I don't think they do anymore due to the reliability problems. But, they shipped them, and installed them in a couple VW chassis. I bet they have an idea on size. https://www.boxeer.com/pages/contact External dimensions on EJs will all be pretty similar. The displacement doesn't matter, but the head style does. The EJ18 was only a phase 1 SOHC (the smallest, fits nicely in both the EA81 and EA82 engine bay), where an EJ20 could be had in all styles (phase 1 and phase 2, SOHC, DOHC and even with AVCS).