That compression will work fine on 91, just need to pay attention to the machine work and try to get all the pistons at zero deck so there's decent squish. Also are you getting that 10.7:1 figure from a calculator that includes piston-deck clearance and head gasket bore/thickness or from the chart given by the stroker kit manufacturer? If it's the latter you should calculate the static compression yourself it might come out lower. I wouldn't be afraid to run 10.7:1 on pump gas though especially with aluminum heads.
