engine build questions?

[BIGBLU 72]

the motor that im going to be building for my 68 long bed. the truck has a th400 and 3.73 posi. im going to be switching to a 700r4 within a year tho. im really wanting 400 hp and a motor that i can drive everyday. ive asked a ton of questions about this so far and thanks for all the help this far.

heres what i have decided on
400 sbc .030 over
stock rod lenght
flat top pistons with 4 1cc relief valves
cam Dur @ .050 214/214 Lift .442/.442
intake performer EPS
Heads Edelbrock 64 cc E-Street
Roller rockers
650 Cfm Holley DP

so i have three questions
1. does this motor sound like it will acheive what i want from it?
2. would i get better power/economy from a set of GMPP Vortec heads
3. am i wasting my time using the stock lenght rods?

thanks for taking the time with ALL MY QUESTIONS i have had about building this motor lol