Well If you like I can get you in touch with the right people for a blow thrue carb turbo motor.
If you are useing a stock 302 block, I would suggest forged internals. You dont need a 4340 steel crank but it wouldnt hurt. The main thing that breaks stock 302 blocks is crank flex. I would suggest that you get a set of Scat or Eagle 4340 H-beam rods and some forged pistons, Probe or SRP are a good bang for the buck in lower hp applications. By lower hp I mean around 600hp or so. You dont need Diamond or JE pistons in a stock block, the block will fail long before those pistons will. Also I would suggest a set of Felpro MLS head gaskets, they are a multi layer steel gasket much like cometics, but you wont have to worry about blowing headgaskets like you would with the blue or "paper" gaskets. The SBF only has 10 head bolts per head, thats 2 per cylinder. This means that you would be more prone to lift a head under boost with a small block ford then you would with a chevy which has 3 bolts per cylinder. But, with the mls gaskets they will or atleast should let go before you melt a piston if the tune is off. Af far as the top end goes since your just looking for 400hp or so I'd suggest some Edelbrock performer rpm heads and a Weiand Xcellerator intake. The F303 camshaft on 1.6 roller rockers would be a nice match. Now for the carb generally the Holley 4150 carbs are the easiest to mod and tune for blow thrue. Do Not buy one of the new Demon blow thrue carbs, they are a mass produced carb that will take tons of tuning and they are currently having problems getting these carbs to move enough fuel for boosted applications. If you want to buy a carb custom built for you I would highly recomend CSU
www.csucarbs.com . They have the absolute best customer service I have ever dealt with. I called Kevin from CSU on a saturday and he helped me tune my car over the phone for some street driving. I have also called Kevin from the dyno and he has been dead on with any adjustments that needed to be made. You wont find that kind of service from Demon, they will tell you they cant help you, it wouldnt be the first time.
Go to
www.turbomustangs.com and do some research in the carb/boosted forums. I am a member there as well and I can promise you that if you follow the suggested methods you will not be dissapointed. Dont skimp on the fuel system, that will make or break your ride. There are a great bunch of guys over at TM.com that do this stuff every day, if you have a question they have your answere.
You dont have to take my advice but I hope you atleast check out the websites I mentioned. They will be a great help to you with your project.
Best of luck to ya!