5 Q's from a soon to be Impreza owner

I will be buying a 97-01 impreza relatively soon and I have a few questions:

1.What years were the SOHC and DOHC? by that I mean did they stop making SOHC at some point and make DOHC only?

2.Did the 2.5 come with SOHC or just the 2.2? and did the 2.2 ever have DOHC?

3. what's the HP/Trq specs for both 2.2 and 2.5 on DOHC and SOHC.

4.Are the SOHC engines worth trying to NA tune for modest but fun power?

5. Is either engine more reliable than the other?

I'm looking to make in or around 200hp without turbo or NOS. I just want a zippy road handler. I'm not sure if the 2.2 would be be worth tuning, or if I need to find a DOHC 2.5 or what.

Any help would be greatly appreciated :smile:

oh, and forgive me if all these questions have already been answered elsewhere, I did a quick thread-title search throuth the first few pages for similar inquaries and didn't find much.

1.What years were the SOHC and DOHC? by that I mean did they stop making SOHC at some point and make DOHC only?
MY98 EJ25 was DOHC / Phase 1 engine
MY99+ are now SOHC / Phase 2 engine

2.Did the 2.5 come with SOHC or just the 2.2? and did the 2.2 ever have DOHC?
EJ25 started with DOHC, MY99 were switched to SOHC. I htink the EJ22's were DOHC....not exactly sure

3. what's the HP/Trq specs for both 2.2 and 2.5 on DOHC and SOHC.
EJ22: 135hp@5400 / 140tq@4400
EJ25: 165hp@5600 / 162tq@4000 (Phase 1)
EJ25: 165hp@5600 / 166tq@4000 (Phase 2)

4.Are the SOHC engines worth trying to NA tune for modest but fun power?
Either will work fine, for me I tend to think you can do more advancing timing with DOHC and make the camshaft open/close overlap for running high engine RPM.

5. Is either engine more reliable than the other?
They say the Phase 1 bock thends to lose the head gasket, but that's only if it's boosted (turboed).

for 200hp at the crank, I'd say go with Cobbtuning camshafts(high lift), port and polish heads (custom or buy new head from Cobb tuning), equal length headers (MRT exhaust system), CAI or use the hood scoop as a ram-air intake system (can be custom with the hood with scoop), pulleys, lightweight flywheel, raise CR to 11:1, and I think that's about it...maybe a few little mods here and there to help keep temps down or something.

Ah, thank you, that was very helpful.