Hi Robbie
Welcome to the world of high performance vintage mustangs, well anything high performance to that matter, they are magnificent when all is good and a pain when things go pear shape, I remember when lance was building this car from scratch and its had some bucks spent on it, ive never seen it on the road myself but I had heard it idling and it had a nice note.
Just one other thing, if you have vintage mustang, its either gotta be a big dollar car that you nurse or a low dollar car that you luv to fix, if its a big dollar car which you like to drive in lets say a spirited manner you either gotta have a sound knowledge of cars and luv to fix em or deep pockets.
Sounds like you don't have a sound knowledge of cars so its deep pockets, what ever you do, don't take short cuts, stick with it and it will come good.
Here you go, just so you don't think your alone, one of my many engine rebuilds.....
luvhev