Trans questions.

[Ghostrider 67]

Can a 4x4 truck 727 be set up for a car? Tails different?
Are the internals of a BB727 and a SB 727 the same?
I have a 1967 SB 727 and a UNK year BB 727 and a 4x4 BB727 on hand.
I want to put a BB 727 behind my 440.
The truck 727 is already mounted on the 440 I will be using hence the question about swapping tail stocks.
Will the truck 727 need a different valve body or what?
I know almost nothing about MOPAR trannys.

Thanks everyone. Ghost.

 

[Bobzilla]

Some internals and externals are interchangeable, but there were many upgrades or differences throughout the years. The easy answer is, just use the BB 727 that has the long tailshaft for a rear wheel drive passenger application.
The long answer is, the 4x4 trans would work IF you swapped the output shaft and tail housing, and IF those parts are compatible. Valve body is not an issue as long it matches the rest of the transmission.
Get the numbers stamped into the flat pad just above the transmission oil pan. That can be searched online for decoding the year.

 

[Ghostrider 67]

Okay, thanks. Now, supposing I want a bit better than stock performance out of the BB727 I have that is a passenger car type?

 

[Cranky]

How much power do you plan on sticking through the trans?

 

[Ghostrider 67]

440 has a M1 single plane, 750 CFM Holley, headers and I suspect it has a mild cam in it. Need to know how to check that as well. HP? Beats me. I also do not know if the heads are stock or have been massaged. This engine was stuck in this truck by a local character who bought it locally in 86. Stories abound about the performance of this truck. It's always told as being a badass truck. Fast. I put my foot in it driving it home and it about snapped my neck. Keeping in mind it's a 86 power ram 4x4 full size truck with 31x10.50 tires.

 

[Bobzilla]

Stock rebuild is plenty strong enough for this mild engine.

 

[Ghostrider 67]

Stock rebuild is plenty strong enough for this mild engine.

Thank you for your help.

 

[Cranky]

I would do a shift kit....but I'm betting it already has one.

 

[Bobzilla]

Don't throw away the 4x4 trans. It does have lots of good parts, or could be sold to a truck guy.

 

[PP1RT]

The 4x4 trans and transfer have some good value to the truck crowd. Sell it. The small block 727 is sought after also. Sell it. Build that BB727 with the $$ from the other 2. Should be able to upgrade some stuff and have more room to walk in the shop.

 

[Ghostrider 67]

Don't throw away the 4x4 trans. It does have lots of good parts, or could be sold to a truck guy.

Oh no worries, I never throw anything away.

 

[Ghostrider 67]

These trucks had an option for a 360 B so it's the same tranny.

 

[oldbee]

Different frt.clutch springs are the most obvious. VB’s are mostly interchangeable IMO. Let’s hope for ‘dvw’ to chime in as my memory is slowly going. You do have an FSM don’t you?

 

[Cranky]

Oh no worries, I never throw anything away.

That was one of my problems. A buddy said to just scrap it all and build my car. After several years of trying to sell the stuff, I'm thinking he was right.

 

[Ghostrider 67]

Different frt.clutch springs are the most obvious. VB’s are mostly interchangeable IMO. Let’s hope for ‘dvw’ to chime in as my memory is slowly going. You do have an FSM don’t you?

View attachment 596504 View attachment 596505 View attachment 596506

yup, and the 727 trans book.

 

[oldbee]

Different springs/weights in governor also.

 

[Bobzilla]

The springs in the clutch packs and governor, and the weights in the governor are not really an interchange issue, they just help tune to each application.
There are differences in the seal rings, spacers, thrust washers, and of course the bands and drums through the years. You just need to make sure the parts being assembled match one another. Similar years are not usually a problem, but parts from a 1970 model year often have many differences from a late 70s or even an 80s vintage unit.

 

[Ghostrider 67]

I will check the serial numbers and castings first.

 

[dvw]

You can use either the ouput shaft, front planetary, and tail shaft from the small block trans. Or swap the 4x4 BB case with the small block case. As long as you have a front drum with 4 frictions (not 3) the rest of the parts will be up to the task. Either valve body can be reprogrammed. If you desire high rpm shifts in D the governor can be upgraded.
Doug

 

[Ghostrider 67]

Thank you everyone for your input and wisdom.