The 66 Mustang has real narrow frame rails opposed to the 67 which is wider. The frame rails really isnt your problem though its going to be the shock towers. The 351 Windsor is a nice swap, if you can get it to fit inbetween the shock towers, I dont think its going to fit with out spreading the shock towers out. The motor is an inch wider than the 289. The best bet would be to swap a 302 in there. Otherwise your not going to be able to remove your exhaust manifold even if you do get it in there. Forget about changing the exhaust manifold gasket while its in the car. And you wont be able to change the spark plugs either. I ran into this problem with the 73 Mavrick, which is basically the same frame. I'd go with a 302, just to let you know. If you have to have the 351 in there, you're gonna have to spread the shock towers out. Thats what I ended up doing and it was a lot more work than it was worth. And if that cars a classic your not gonna want to cut it up. I'm going to work until tonight, I'll check this out tonight if you have any more questions, I'll try to answer them later.


~ Vegas ~