Well I think I can speak on this subject since I just finished mine (CSX4766) Nothing on this car is real hard but it does take time to do it right. I used a slave cylinder and that took time to engineer a bracket and arm. Fuel line and
oil lines all take time as well. Wiring Batteries, MSD, distributor more time, Then getting the shifter right is more time as well. The are not that hard to do but again require lots of time. $5000 sounds about what I would charge if someone asked me to do it.
Morgan