..

 

1000 miles, change gear regular, don't go over 4000rpm much and don't let it strain in any gear.

 

As above moderate driving with a little boost every now and again. Every builder has their own opinion on this, I was recommended a couple of hundred miles using a mineral oil (synthetic provides too much protection for rings to bed in correctly) drop the oil and replace with quality oil with a new filter

 

Crank and bearings all the same and no machine work to block or heads i should have added .

 

why only change the pistons?

 

Cracked ringlands

 

If you have dropped new piston/rings into original untreated bores there basically is nothing to bed into, as a basic requirement they need a glaze buster in them to give the ring a chance to bed into the bore finish.

 

I would have thought cross hatching of the bores and new rings would have been beneficial while the pistons are out?

 

Holy cow, who advised you just to do the pistons?