S, I have currently a 360 mated to a NP435 transmission. I may buy a 74(he believes) block and heads and considering the year (if correct), it should mate to the transmission, only if it's internally balanced, correct? If externally, then replacing the bell housing. I'm not looking for say high HP, but more of a Tq for a larger tire and lift later on in the build. My other thought was just bolting a blower to the 360 and rebuilding it to a 390, etc or a stroker. I'll be getting the casting numbers from the block this weekend and will know better on the year, etc.

 

All 429 and 460 engines up to 1979 were internally balanced. It is easy to tell the difference by looking at the spacer that's behind the balancer at the front of the engine. If there is no hatchet shaped weight on the spacer then it is the internally balanced version. Finding a 4 speed bell housing for a 460 might be difficult. There were no internally balanced 460s that were built with a manual transmission, all are automatics. Later when a manual was used behind a 460 it was after they went to the externally balanced assembly and they use a flywheel with a weight. Bell housing pattern is the same.

 

Pull the 360 and refresh it with a stroker kit, 428 crank will get you 410 but kits are available for up to 445 ci
429/460’s are good engines but are about 100 lb heavier than a FE, aluminum intake will take nearly 50 lb off an FE’s weight
429/460 will not bolt to a FE bell housing, you’ll need a bell housing from a 351M/400 to work with your transmission. 429/460 passenger car right side manifold requires notching to upper frame rail for exhaust clearance (sometimes I don’t recommend), pickup right side manifolds have been difficult to find for years so headers will be your best choice. Your also probably looking at a aftermarket rear sump oil pan for that 429/460 swap

 

While you can make the 351M bell housing work because the bolt pattern is the same the depth is not correct so it isn't "plug and play". It requires some specialized hardware to make it work.

 

I’ve never done the conversion but the 77 F-150 I purchased in 83 had been swapped from 351M to 429, I later did a 400 C6 swap and the guy I traded with used the transmission and bell housing behind a 351M
I don’t know what would have been done for the original swap but it didn’t appear to effect the reverse swap

 

The depth on the C6 is the same because the offset in the flexplate is different but on the stick shift to make it work takes a special flywheel to make up for the difference. The reason is because the 400 is like a 302, 351W etc on the back whereas the 429 and 460 are like an FE depth wise.