Damn I have been out of the game to long. Lol when I built my 73 dart I think the TTI headers cost me $690 shipped and the conversion engine mounts was around $140. I was going from a 904 to a 727 so I had to have a drive shaft anyway. I just had a 7290 ujoint size drive shaft from a B-body shortened for the dart. Also a aluminum headed 440 doesn't weigh much more than a small block. But if you think the small block fits your needs better. Then that's cool. Got any pics of your car? I used to own a 1973 dart sport that I put a 360 in.