Do i need to make any change's with fuel pressure or injectors , chip.need help thank you for any help.

 

Provided everything remains close to stock, just swap everything from one engine to the other, including the ECM. Now as far as the injectors go, the 305 injectors(19 lbs./hr.) are good for about 355HP so you can use them and just increase the fuel pressure to about 50 psi. The 350 injectors (22 lbs./hr.) are good for 450HP and you will need them if you are planning on modifying the engine. Remember that the 305 injectors are smaller and therefore when you increase the fuel pressure it will put more strain on the fuel pump. The injectors too will have to work a little harder since the coil has to open the pintle under a greater pressure in order to provide the engine the amount of fuel it's needing.
If it were me, I would use the 305 injectors if the engine will be producing well under 355HP. They will deliver the fuel the engine needs and because it's under a greater pressure you will benefit from better atomization. This in turn will produce more horsepower and better fuel economy.
If you are going build the engine for maximim HP then go with bigger injectors and get a new PROM.
Latter,
Ozzy

 

One other thing. The knock sensors are different. You will need a 350 specific sensor.