I知 engine swapping my Camaro, it originally had a 305 in it. I知 buying a 383 blue print engine from summit racing, I知 wondering since the new engine makes more than double the hp (440)as the stock engine will I need to upgrade my transmission or rear end?

Need? No. Are you going to use 350 hp of that 440 hp? You are? Then yes, yes you will. The axles and transmissions and chassis and brakes and well everything, are fairly weak in our cars. Modifying a thirdgen for more power equals a lifelong project usually. But that's part of the fun. Good luck!

It all depends on how hard you are on it as to when the trans & rear end will go out. Might be more convenient for you to rebuild the trans when you do the swap rather than wait until it goes out.

The OEM transmission and rear end are not rated for that much power. They will live for a while if you are nice to them, but you should be planning for upgrades.