If your taliking cossie yb which i think you are id go for a full rebuild

Block to be bored with new pistons and machined for long stud kit ,rods rebushed,crank checked for tolerances,oil pump rebuilt or replaced.
Head fully rebuilt by niel roper or nick waples,new lifters and springs from newman cams with a trick inlet cam..around 11mm lift with 280 duration would do it,std exhaust cam for better pick up and big torque..
Inlet plenum spacer or even better hart plenum aswell as some 83lb injectors and with a good re map or even better a newer after market ecu and remap and you would have an engine capable of over 500 hp with the right turbo