I have a 8 wire bryant thermostat model p271-3457 that I want to convert to a hunter model 42995b but it only has a five wire diagram

Wrong tstat,, from what I`m finding the 42995b isn`t compatablefor heatpump use
When you take it back,, pay a little more and get a honeywell,, hunters are junk,you would be very lucky if it lasts 3 months

I agree with wmprop