z1000 barrels on z1 900 block

Hi to all Z 1 fanatics, am restoring a 75 Z1B 900 in Australia the engine number confirms a 900 block, the barrels have the 1015 stamping on the raised section lower RH side but the heads still have the 6mm studs, believe the z1000 went to 8mm, so my question is can the barrels be fitted to the block and still utilise the 900 heads, appreciate any feed back
Thanks
Bob

Yes. The Z1900/KZ900 heads fit on 1977-1980 KZ1000 blocks with proper head gaskets no problem.

The barrel etc will fit.
Just check that the case mouths are large enough for the liner spigots.
Some early 900 cases need some slight clearancing fore and aft for the 1015 spigots to drop in..