Header question

Hi Fella's. I have a 69 Cuda convertible and I have just found a replacement 383/727 combo for the tired old 360/904. It was one of the /6 cars but I think it has the V8 k-member now, how can I tell? Also I have some headers that I bought for a B body, would they fit with the power steering and with a cable operated shifter? What motor mounts am I going to need? Anything else ya reckon I need? Already has 8 & 3/4 and disc brakes up front, no booster though (will a booster even fit?)
Love your work fella's....