Welcome to CHR! We're glad you stopped by and hope you decide to stay. Lots of good ol' hot rode folks here. Need a bit more information on your build:

Do you have some numbers for the heads and the cam? Heavy duty can mean a lot of things from valve springs to screw-in studs to hardened seats, etc. The term "RV cam" is all over the place and while it typically means the cam is ground to produce torque low in the RPM range that's not always true.

Do you know the compression ratio?

TBI stands for Throttle Body Injection so I'm thinking that you kept the TBI intake manifold and do not have a carburetor?

What vehicle is this going into?

What transmission? If automatic, stock or aftermarket stall converter?

What rear end ratio?

What is your goal with the engine - i.e., street cruiser, daily driver or?

Fill in the blanks and we can help you out.
Glenn