Rocket

You can safely run 85mm Bore using a 85mm bore Cometic head gasket.

Head gasket sealing is a bigger concern with the larger bores than cylinder strength as the sleeves are pretty strong due to the manufacturing process of being centrifigully spun cast. (creates a denser cylinder).

As for welding, you don't need the plate that JG puts on their blocks. Golden Eagle sleeves are located by tangs placed in betwen the sleeve and CNC'd inner portion of the water jacket allowing for a modified opend deck that allows for more even cylinder cooling and less heat retention in the upper cylinder. This prevents detonation as the end gases near the cylinder walls are exposed to less heat.

Late,