looking for wisdom 1960 GMC build

[animals speed shop]

We are getting ready to start a 1960 GMC long box fleetside and am putting a build plan together . Wondering if some of you have blazed down this path before and can help me out I havent built alot of the 60-62's .

- Planning on a crossmember swap to a 73-87 which i think i need to lift the engine mounts ?

-Power steering upgrade

- Change bolt pattern to 5x5 bolt front and rear

- I want to use a narrower rear end with posi and rear disc brakes to give me a deeper dish rim look. Anyone have any ideas what to use ?

- Its getting a 600hp 383 stroker thats built and dynoed already with a 700R to take the hp

- 4 wheel disc brakes

- Static drop 5" front and back

This is what we want to get into the build with a few trick things added in ...So anyone who has any information that can help us out and help me out with cutting down my research time that woukld be awesome ......Thanks in advance