Well I'm back for more info / guidance. I am now sure my project car is a 1971 Impala Custom, supposedly a 400 small block.

The reason I say supposedly is that I was told I might want to check the motor mounts and in doing so noticed that the lower front Tab or bolt hole on either side of the cross member actually has no bolt and hangs out past the cross member, essentially holding the motor in place with 3 bolts on either side.

The Motor does not raise or lift up when the throttle is applied but this also raises a question in my mind if this is indeed a 400 small block? I was told the motor was replaced at 20,000 miles by the Dealership under warranty but I suspect they may have put in something other than what the car originally came with otherwise everything would line up as it did from the factory.
I can't think of any other reason for the motor to be to far forward so that the motor mounts would not line up?

I have not yet located any numbers on the block as I need to degrease the engine from an oil leak and 30 plus years of road grim and lack of engine compartment cleaning.

Other things I have noticed is the Heater and Air Conditioning does not work and no air blows threw the vents? I probably will check fusses first but I also noticed the Air Conditioning belt to the compressor is missing. I don't think this would have anything to do with air not blowing inside the car?

I wanted to put a chrome dress up kit on the air filter and valve covers but there are a lot of vacuum hoses and also a pipe running from the header to the air intake? The air intake reads something about turbo 400 something or other and I suspect this is what they are referring to?

Ideas, info or suggestions welcome please.