For the rack, don't waste money on it. Cut the hydraulic lines from the valve body to the rams and it will be manual without locking up. Drove my old Capri like that for a few years, no sweat. The march kit sucks, period, I've home built better setups. It allows too much deflection and is a bear to set up.
You can run a non serpentine water pump and redrill your pulleys to keep the serp belt and run a triangle belt setup without the tensioner. Just grab a early style alt tensioner and flip it over and go to the top of the alt on the stock 5.0 bracket. Cut your stock belt to get a wrap length and get a belt on either side of that and try them out. Take the one that doesn't fit very well back. Did that on the Capri too withthe 351 and TT setup. Just takes a little thought and effort to make it work fine.
Jamie