Need help asap

[J_PEPIN87]

Well i got the big block in my truck got everything bolted and went to start it for the first time and i barely got it running.wat i mean by this is that the starter was dragging a lot.got the engine running for like 5 minutes at 2k rpms and everything was good, good oil pressure,temp wasnt dat hot,no unusual sounds at least that i could hear over the exhaust.and then the throttle came loose(i didnt have it hooked up) and the engine died. After this i tried to get the engine running again it would barely turn over so i thought it was the battery.got a fully charged battery and the same thing.went to turn the crank over by hand and is extremely tight even with the plugs out i can barely turn it over.my question is should it be this tight?the engine is a complete rebuild.i have asked several guys and they say dat is normal for it to be this tight,i just dont want to mess anything up.