Most likely re-used your RS manifold. Makes everything plug and play that way. Engine number is on rear passenger side of the block. There is a flat spot on the corner, it'll be stamped there.

look for a sticker on the timing cover and also one on the back of the LHS cylinder head to find the engine number

__________________
2000 WRX - Grip King
1997 Sileighty - Gate Monster

That's what I was going to say, if they had retained the original red manifold it would have been a complete headfuck doing the wiring, it's got a V3 power steering pump and header tank so I think you'd be pretty safe, just a shame it's not got the V3 computer (different plugs) as they are one of the best factory computers out there, but great cams and forgies, sort of the wholly grail of Subi motors before the 207.

__________________
Beaten up old 98 Gen 2 Liberty, 13.0, stock V3 STI running gear.
07 Transit motor home
69 VF & 70 VG Valiants needing full restoration
Yamaha Zooma 50cc rocket hopefully going with the Transit.

Thanks again for the helpful opinions guys, shall sit back and enjoy it, responsibly of course.

__________________
91 GX Wagon, V2 STi RA conversion.
08 HSV Grange "The boat"
16 WRX STi

One thing you could look for is a V2 STI RA computer, they usually go for around the $250 mark and will help it along nicely.

__________________
Beaten up old 98 Gen 2 Liberty, 13.0, stock V3 STI running gear.
07 Transit motor home
69 VF & 70 VG Valiants needing full restoration
Yamaha Zooma 50cc rocket hopefully going with the Transit.

Ribbed cam covers are circa 1996 (version 2) or older. Version 3 onwards has flat cam covers.