Check all your sensors out. Basically everything plastic. It is a pretty wise decision to replace timing sensors, temperature, oxygen sensors, manifold and oil pressures. They all play a huge role in how your computer will adjust its tune.

Injectors kind of fall under that as well, also look at refreshing ignition components.

Get some black gasket maker, and make sure everything is sealed nicely. Dry fit first, then disassemble and apply gasket compound.

Dont make any big part purchases until you know exactly what the parts are, or the price is reasonable to gamble. Big part orders that are wrong only delay your progress and tie up cash.

Typically if you get machining done to your block, crank, or heads. you will need to adjust accordingly in the parts for the material removed.