Building a 2.3 with 90.5 Wossner pistons, head gasket issues?

Hey Saab World, I'm rebuilding and going with a set of Wossner 90.5 mm forged pistons. It's about the same price to bore and go forged as it is to sleeve all four and re-bore to stock and then use stock pistons that I'd probably break again. I'm wondering about the head gasket bore now that I need another .5mm diameter. Is the diameter on a head gasket big enough to accommodate the 90.5 dia bore or do I need to modify my head gasket? If I do need to trim my head gasket, any suggestions or directions? I have no immediate plans to tune it, (I'm not a responsible adult.) Will my Wossner rings likely be pre-gapped correctly? Anyone with Wossner ring sizing experience? Thank you! Dale in Roy, Utah