Agree with Shaun. The TBI (both the actual throttle body and injectors, maybe even the stock fuel pump) won't support a healthy 383. Yes, they will bolt on, you might as well bolt a 2 barrel carburetor on there instead, it would be just as much a waste of time.

BBC TBI unit/injectors, and PROM tune may get you there. Will need to check fuel pressure after the swap to ensure it can feed the motor under all throttle conditions.

Yes.The only parts that get changed which turns it from a 350 into a 383 are the crank,rods,and pistons.Bore the block .030 over and install the new parts.I'm not sure if the bottom of the cylinder walls have to be notched or not to clear the rod bolts so you'll have to check into that.Below is a list of typical bore stroke and ci displacement

4.000" bore 3.48" stroke=350ci

4.030" bore 3.48" stroke=355ci

4.000" bore 3.75" stroke=377ci

4.030" bore 3.75" stroke=383ci

You can also use a 400 block that's bored .060 over to make a 383

4.185" bore 3.48" stroke=383 if using a 400 block bored .060 over

The stock TBI unit isn't going to support a 383.

camshaftshaun@gmail.com

you shouldn't have a fuel problem unless you are planning to rev higher than 5000rpm,,,you will also need to not use short 400 rods but use longer 350 rods and pistons with off set pins... if you want it to live ,,,there are also different grades of connecting rods