Will a manual trans from a big block bolt to a small block?

[btalley]

Hello All,
I have a 4 speed from a big block FE engine. Will this work with a small block by just changing out the bell housing?

Thanks for any info.

B.

[Roger Carter]

Hello,
There are differences in the input shaft lengths between big and small block manual transmissions. Typically the difference is in the length of the pilot on the input, the part that seats in the pilot bushing. The small block is usually longer than the big block. Since you are using a big block trans there should not be any issues.
Before you bolt everything up take a few measurements to be sure there is no interference and there is proper engagement of all parts.
Other than this pilot length issue the trans should fit fine.
Hope this helps. Good luck.
Riger Carter

[66Rat]

there are only 2 input shafts for the top loader 4 speed one for big bocks and one for small blocks. but the input shaft ford the 390 is the same as the small block when i get back to my computer i will give you a link on the 4 speed.

[Hawkrod]

Unfortunately you did not provide enough info to properly answer the question thouroughly. There are 3 different input shafts used on 4 speeds in Ford vehicles with FE engines. A truck 4 speed uses the same input as a small block which is why truck bellhousings don't work on cars,the second input is a car input and it is slightly shorter than a truck or small block trans and Ford even makes a pilot bushing for this application (it is a slightly longer bushing for better engagement), and finally the 427/428/429 big input trans which is short like a 390 but bigger around and uses a different clutch. They can all be used behind a smallblock with the right combination of parts. You also did not mention what year smallblock and 64 and older uses a different bellhousing than 65 and newer and that can also affect trans mounting as they use different input supports and case bolt patterns. Some details will help narrow down exactly what you will need. Hawkrod

[btalley]

Hey Guys,
Thanks for all the input. Actually, what I have is a 1979 Bronco frame that I would like to put a 66 cab and front end on. I also have a small block from a 65 Mustang I would like to use for the engine.

The Bronco has the bigest freakin 4 speed transmission I've ever seen connected to the transfer case. Although the transmission is huge, the bell housing and input shaft connected to a 400m look normal so I was wondering if a bell housing change would make this work. I don't have a bell housing for the small block to compare it with. The more I look at the engine mounts for the Bronco, the more I think this will not work without some major fabrication.

So, to add another question, is a 460 block a direct swap with the 351/400m series engines.

Thanks for any info.

[Roger Carter]

Hello,
Whether you go with a small block or the 429-460 your front mounts and/or bellhousing will need to change.
The 429-460 will bolt to your 400 bellhousing, but there are no factory mounts to put it in your truck. There are aftermarket mounts, as well as several different ways to "modify" several different stock type mounts, to bolt the engine in.
With a small block you will need to swap out the frame stands for a set from a small block truck, use the appropriate mounts, and change the bellhousing, as previously discussed.
The long and short of it is... You can put a small block in using all factory parts. To put a 429-460 in you need "special" or non stock parts. Regardless of which way you decide to go, there will be many, many odd and assorted pieces to complete the swap. I always try to have a donor vehicle, similar to what I am working on, with the same drivetrain as I am swapping in.
Good luck.

Roger Carter

[Hawkrod]

Okay, now is where it gets sticky. There are two different flavors of 1965 Mustangs and they are very different engine wise. If you have an early production 65 with a generator it is what is commonly known as a 64 1/2 (Ford never callled them that). The 64 1/2 cars use a 5 bolt bellhousing while the later cars used a redesigned block with 6 bolts on the bellhousing. If you have one of the early engines it can't be used with that trans unless you have an adapter. If you have a later engine it is a pure bolt on situation. Hawkrod