1998 Chevrolet Camaro over heating

hi jackspades still trying to resolve my engine overheating only under hard acceleration & all water related parts been fitted brand new,my thermostat has now been removed & is slightly better ,do i still need to remove air from coolant & if yes where do. brand new bigger radiator ,new water pump,thermostst housing(t/stat removed), sensors,new oil cooler outside radiator,all air con & heater
disconnected, water pipes some are stainless steel.fan working & blades are fine, heads & gasket skimmed & renewed & tested .excellent quality 3l coolant.
in flat & traffic where mimium acceleration is required the heat guage needle is at quarter mark ,only uphills mostly & hard accelerationi the needle can climb all the way to topnearly red then i lean of pedal,have spent a fortune already i'm now waiting for a miracle answer.