Props are different.. - I have a W58 front prop forsale and maybe a 154 one - You'll have to have one made to measure.. Every engine conversion is different.. Can depend on what engine, what mounts, what car, etc etc..
I have a company local to me that made & balanced my 1 piece prop for £150.. I just supplied both ends and a length.
Think gear shifters are different.. - I may have a 154 remote shifter forsale, which you'll need for an s-body conversion
And Slave cylinders are most definatly different... I have about 5 W58 Slave Cyl's forsale.. I do have an 154 slave but it's part of a kit..
What box do you have?