Swap 348 into 1959 apache 3600

[348 Patchy build]

I am building a 348 to go in place on my 235 in my 1959 Apache 3600.
I currently have the SM420 manual 4 speed box.
Will I need a different Bell Housing and Flywheel for this swap?

 

[La Hot Rods]

Yes you will.

 

[348 Patchy build]

Thanks La Hot Rods. Do you have any information on what bell housing will do the job? Any genuine numbers I can search for?

 

[La Hot Rods]

If you can find the bellhousing and flywheel from a 8 cylinder truck you should be good if you plan on using the side bellhousing mounts.

 

[La Hot Rods]

I should add the bellhousing needs to be for a 4 speed as it will have a larger front bearing retainer than the 3 speed.

 

[348 Patchy build]

The 348 came from a 1960 Impala. Are the SM420 car boxes smaller than the truck ones?

 

[32witha409]

The SM420 is a truck transmission. Used in 1/2, 3/4 and 1 ton trucks. The car box would have been a t-10 or m20 and yes they are smaller than the SM420

 

[348 Patchy build]

Thanks guys. Very helpful

 

[409Kid]

When I had my 61 C 30 dually it had a 348 and SM420 in it when I got it. When the 348 finally died I put a QA 409 with a T-400 in its place. In addition to what has already been said you’ ll need a front saddle mount for the engine. I don’t know if the 6 cylinder saddle is interchangeable. But a V- 8 will. You may have to relocate the block mounting holes in the mount if using an early SBC mount. The Chevy V8 truck saddle mount may be the same as a tri five passenger V8 saddle. Someone else may know the interchange for sure.

 

[348 Patchy build]

I have already found a tubular fabricated mount system that lets me use small block mounts. That’s the easy part! I got a car box that looks identical to the original SM420.
Would the car box work in my 3600?
Or is it too light for the 3600?

 

[64ss409]

Cars didn't use a top loader 4 speed. Can you post a photo?

 

[348 Patchy build]

Righto. Sorry about the quality of these, but here we go. The first lot of pictures are of the bell housing 3815891, and then the transmission 3837334 that l got that l was told came out of a 1960 Impala.
Can anyone tell me what l have here?!

 

[348 Patchy build]

3761930 is the casting number of the box l l have in the Apache at the moment.

 

[409newby]

Yeah that’s a truck only transmission should work fine behind your 348

 

[348 Patchy build]

Beautiful. So l have a spare

 

[348 Patchy build]

This is my 348 in it’s original clothes

 

[Jim Sullivan]

Is that a truck bell housing that needs an adapter plate?

 

[64ss409]

The pickups and the light duty trucks, Viking 60 and lighter, in those years didn't use the adapter plate.

 

[348 Patchy build]

So I have a trans with the casting 3837334. And one with the casting number 3761930.
Which would you think is a better box? Or is the really no real difference in them.

 

[La Hot Rods]

I would have a look see of the insides of both then figure from there. Both will be a granny low truck box with the un synchro low gear.
Not sure of what your intended use is for this truck.