Following on from my original thread as a newbie - Thank you all for your valuable advice in building up my A15 race motor!
I used a combination of advice/torque specs from this forum and a Hayness 1200 manual to build it up,as I'm not a mechanic by profession and not familiar with Datto motors (I have built quite a few VW race motors though).
It took so long due to problems finding parts for it. I stripped the thing to find a partially blown headgasket and some moderate corrosion of the alluminuim around some of the offending water jackets - the head was slightly warped as well,and two of the cyllinders had been burning oil - probably due to excessive rich running/bore wash as everything was pretty well carboned up.
The main bearings were OK,but the bigends showed advanced normal wear as in a high mileage motor. Fortunately the bores only needed honing and the crank a good polish. The pistons could be re-used as well.
The big problem was that the A15 was never sold in South Africa,and although the A15 shares most spares with the freely available A14,the piston rings were totally different.
I eventually ended up using 40thou oversize Hyundai 1.6 Elantra top compression rings,Toyota Corolla 2nd compression rings and A14 oil rings

.I had the head pressure tested,skimmed,flowed,seats redone,manifold water ports welded up and valves re-faced. I also fitted new freeze plugs and had the block deck resurfaced.
There was the usual issue with the engine mounts not lining up ,but everything else fitted perfectly.
It was thus with a slight feeling of trepidation that I swung her a few times with the plugs out to prime the oil galleries,and as soon as the oil light went out,I refitted the plugs,enerised the coil and started her up.
It caught on the second swing with a throaty bellow (no downpipe yet)and settled in a slightly cammy idle (268 deg cam).
These noisy start-ups always seem to happen on Sunday evenings - poor neighbours

.
I'll finish up tonight,take her for a drive and keep you all posted on the dyno figures

Thanks to all the guys that helped out with advice -especially Dattoman,Dodgeman and Flydatto