903 head on a 1015 block?

I'm in the process of doing a rebuild of my 1976 Kz900 and will be using a newly acquired 1015 block which has been honed to 70.25mm. Am I safe using the original 903 head which was obviously designed to be used with a block bored to only 66mm? Will the "overlap of 2mm make any difference or cause any problems? Thanks.

I think you will be just fine. You will need the matching valve cover if you were using a 1015 smog style head previously and will also need to use the 1015cc head gasket.

WG,
Plan on using all the original 903 (1976) bits above the head gasket but WAS indeed planning on using the 1015 head gasket. Probably going to take the whole lot out this weekend, tranny & all, strip it all to the nuts, clean and reassemble with some of the "spares" I have lying around, if they are in any better shape than what's already in there. Thanks.

I ran a 900 head on my Z1 Classic. No problems. Roy