Welcome to the site
Gve us an idea of what your plans are
You want a v 8 K but what are the plans? There are motor mounts that will allow you to use what you have and put a small block or big block in it with 6 K
Also it isn't that hard to do, the torsion bars need to be removed correctly, READ THE MANUAL if you are unfamiliar with the process
Others are correct about the GT, not available in 74, unless you have an export or built other than in USA, then maybe they did have a GT. seen some strange stuff from outsideUS.