Hello, this my first post here, I will try to keep it short. I am putting a 1987 454 tbi in my 1980 chevy truck with 4l80 tranny. I am not sure what vacuum line I need, do I need vacuum canister?

The engine will start but it is running rich, showing code 33, low vacuum. Also the engine is running hot, thermastat does not open, had 2 thermastat in, spring pointed down. Runs cool with out thermastat. I have line coming out of tb to heater core then back to radiator, is this correct?

Thanks for any help.