This looks just great, Ken. With the lighter Z motor, you might want to think about lowering the front end, looks like it's riding a little high. It's an easy fix. You can get some longer bolts that hold the spring pan to the A arms. Also get some lengths of allthread. Remove two of the bolts holding in the spring pan and insert the allthread and install nuts on each end. Remove the other two bolts and then slowly undo the nuts on the allthread until the spring tension releases and you can remove the spring. Install the longer bolts and insert a couple of nuts between the bottom of the A arm and the spring pan, which will lower the pan. Bolt everything back up together.
The Z swap caused a huge kerfluffle in the Healey club magazines back in the early 90s. Mark Lambert from Nashville, TN did the swap, which was featured in the club mags. The purists grabbed their torches and pitchforks, but Mark fired back in defense, with each side having its proponents. There were stories that Datsun had bought a 3000 to use in designing the original Z, who knows?