I'm looking at doing a quick/easy freshen up on my engine - I'm an Aircraft mechanic so do know the basics and am reasonably competent at swinging spanners - the specific things I'm looking at doing are:
1. Fit new high volume oil pump
2. Do the chain guides (motor mechs rooted something when I had the timing gear all done about 2 years ago - now something's busted ie. part of one of the guides - shoulda f**k done it myself!!!).
3. Chuck new rings in - possibly pistons too (fan belt broke about 3 years ago and the engine got Veeeery hot - still runs fine and makes great power but at least no 3 cylinder is burning oil - ie. rings have lost tension and/or bore glazed).

The first is straight forward tho I may raise another topic to try and find out where to source one - have yet to call repco or Coventrys tho.

The third is a concern as I'm worried that the bores in my 300 000 km engine may be too out of round and new rings will actually bugger it (won't bed in at all) - does anyone know whether the bores in these I6's go particularly badly oval??

1. Should have no problems getting a new oil pump (any auto store will have it or be able to get one in).
2. Just need a timing chain kit ($80-$120 depending where you go). Will include gaskets, seals, chain, sprockets and guides.
3. 300,000 might be a bit much for a hone and re-ring. Just measure it up though. The limits are 0.127mm for out of round and 0.254mm for taper, anything close to that and id get a bore and hone. Should be able to get bore, hone, and new pistons and rings for ~$400.

Plan A is to do the hone/ring job without having to drop the crank out - can a shop do rebore etc. with the crank still in the block? (REALLY don't want to stuff about with rear main seal - it's not leaking so don't want to disturb it - and bearings unless it's absolutely necessary - aiming to have her all done from engine out to back in and running in one day).

Bit of a waste of time to do rings without bearings IMO. The bearings are cheap and easy, same with the rear main seal, the hard/expensive part is the labor to get to them and you'll already be there. It will take like 15m extra to do the bearings and rear main seal.

Other option would be to buy a 2nd hand engine, recon that and then just swap them in one day. You could probably get a 4.0 long engine with 300,000k's on it to recon for $100 if you look around then you take take all the time you like.

Yeah,.... I've been tossing up whether to go that way - time is a bit against me as I'm not sure how long whatever those d***head stuffed under the timing cover will hold out (idiot that did it was meant to be the workshop's "Ford Guru" but for a start the peanut put Blue Max silastic ALL over the tensioner housing threads!! - not to mention having the cam gear one tooth out - which in the process of fixing was how I discovered Blue Max all over the place) - I guess I could just redo that tho I'd rather include it with the bigger workover and with the engine out - I'll think on the whole thing a bit more. Thanks for the feedback.