Car Wont Start.... Help?
 

So i have a 1997 Firebird formula with a 350 lt1 and i recently changed the heads and gaskets (due to overheating). i decided while i was this far in the motor that i might as well rebuild the interior top half (lifters, pushrods, timing chain, etc) and now i have everything back together but the car wont start.
The problem im having is when i first crank it, it rolls over perfectly fine like 6 or so times then it slows down drastically, almost like a sluggish uneven crank. When i press the gas pedal all the way down and crank it, it begins with the sluggish slow cranking then clears right up, but still wont start unless starter fluid is added in. Now when it does start it wont idle as i barely have to give it any gas to keep it from stalling out and dying. Could this be a bad fuel pump flooding the engine or what should i look into here? the alternator, battery, and starter are all brand new.

Sounds like its not getting the correct amount of fuel.

Double check your wiring and vacuum lines. Make sure everything is going where its supposed to.

So i hooked up a fuel pressure tester to the fuel rail today, and when i turn the key one click the pressure jumps up to 45 then in about 2 seconds drops down and holds at about 30.... im not so sure if this is normal but if not what could be the cause of this? stuck open fuel injector? fuel pressure regulator?