1303r wrote:now have 1bar max when hot

. must have buggered something up. - could it be a problem with the rockers/pushrods/etc?
Now I don't want to sound rude, honestly I don't, but if you think that low oil pressure could be something to do with the rockers or pushrods then you simple don't know enough about engines to be doing such work as removing heads and changing big end bearings.
Also taking the heads of these motors to "check it over" as you mention is really not a good idea because of the way the studs are designed. One often finishes up causing huge problems with broken studs, sometimes resulting in a replacement engine being needed !!
The only likely cause I can guess at is that you may not have torqued the big end bolts down properly ( you did use NEW big end bolts didn't you ?? )
Re Gaskets - GSF are who most folks use for gaskets and the like so I reckon they must be the best source.
Let us know how you get on
