Approximate Cost to Buld 375-400hp 360?

If you have the long block, that will save a lot of money, not having to buy little stuff. For 400 hp you could use the stock crank and rods, heads with a little pocket port, even the stock rockers if they are in good shape will work fine. Shoot for 10. To 1, a cam in the 480ish lift with around 235 to 244 @.050 duration, rpm air gap or LD 340 intake block the heat crossover, and a 750 holley with headers.