The majority of us use the info here when doing a swap in a '54-59 Ford: http://www.jalopyjournal.com/forum/threads/faq-sticky.897329/ The Butch's kit's are OK for 1953 and earlier more info on mounts can be found here: http://www.jalopyjournal.com/forum/media/albums/289-302-351w-swap-mounts.41498/
I used Butchs motor mounts in my 55 Victoria with a 302 an c-4 good stuff real good fitting brackets and i liked the round rubber mounts they are made very well
Slicks,how about posting some pictures? High lighting exhaust to steering box which can be a concern.
I used those mounts when I put a 351 windsor in the 54. The motor was from a 1974 Torino, and I used the Torino exhaust manifolds. They were quite close to the rubber cookies, and the heat collapsed the cookies. That made everything vibrate. I changed the cookies several times for the problem. I finally solved the problem by getting rid of the windsor and putting in a 390. So beware of having the exhaust too close to those cookie mounts
That's what I thought would be a concern too,also since most of those "cookies" are now made from inferior offshore rubber there has been postings about them failing on several sites within or before a year of use,using the late Mustang mounts will keep the heat further away from the mount.If you use the Butch's I would at least swap out the rubber for Energy Suspension replacements made of polyurethane.
Swapping the rubber for urethane does not work either. The heat bakes the urethane until it is like a solid mount. The only advantage was the motor did not drop down, like when the rubber collapsed