Like the fact you've used the Toymota. They gotta be one of the strongest stock 8s around now.
years ago my mate had a Mk1 Capri with 4 bolt 350 in it, went like fuck in a straight line but didnt handle very well. Yours should be primo as the weight factor nowhere near that of a 350.
I also know a dude who had a Mk2 with 351 windsor and c4. He used Leyland P76 struts and they seemed to work well, pretty sure he plated and re studded top of strt tower to fit.