Went through this with the newer k, and hemi & crossram intake in my '64 savoy, (put the original k back in)- unless your racing and need that tiny bit that would help you set a new world record, don't mess with it. In my opinion, it's not worth all the other mods you have to do, firewall clearance, plus your header clearance, transmission cross member, etc, etc..And if it's a 4-gear, now you have opened a bigger can of worms, - clutch linkage, Z-bar, etc, etc. I'm doing my '62 fury right now, MAX WEDGE intake & heads, 4- speed, and went with a factory original '63-65 k-frame, mounts and insulators. Used TTI headers, very easy, and everything fit great, and had lots of clearance everywhere. But if your racing , and need that small one thousandth of a second, go for it. Lots of racers have done it. A lot of extra work.............if you like a challenge, go for it.