Small to big block

[1973]

Hi I was wondering what all needs to be done to swap in a 383 or 440 in place of a 318 in a 1973 barracuda, does anything need to be done with the K frame?

thank you

 

[74 challenger]

you will have to change tranny,drive shaft,radiator,wiring harness. i have a 318 challenger and decided to put a 360 in it. Also was told the car does not handle as well with the bb. torsion bars should be replaced also. Let us know what you end up doing. Good luck

 

[sheetmetaldan]

you will have to change tranny,drive shaft,radiator,wiring harness. i have a 318 challenger and decided to put a 360 in it. Also was told the car does not handle as well with the bb. torsion bars should be replaced also. Let us know what you end up doing. Good luck

Correct me if i`m wrong but doesn`t a 727 tranny work with big or small blocks. The 904 will not work with BB. The original poster never specified what tranny he has now if any.

 

[Chryco Psycho]

the 727 for big block & small block is identical Internally but the case is different between small & big block . Most 318s have the 904 , 340 had the 727 .
The engine mounts are different but the K frame will accept any V8 Except the Hemi without modification .

 

[sheetmetaldan]

the 727 for big block & small block is identical Internally but the case is different between small & big block . Most 318s have the 904 , 340 had the 727 .
The engine mounts are different but the K frame will accept any V8 Except the Hemi without modification .

Thanks for the education I didnt know that I thought 727`s were all the same inside and out. If anyone has pics of bb/sb 727`s for comparison I would appreciate it.

 

[Chryco Psycho]

the belhousing is different starter sits in a slightly lower spot on the small block

 

[moparleo]

Naturally, he needs belts,hoses,exhaust manifolds and headpipes, possible fuel line upgrade depending on state of 440 build.

 

[1973]

thank you all for the info, not sure of the tranny, it is all stock right now though, i have a big block 727 to go in, will all my stock shifter stuff work- (slap stick floor shift) also i have a cordoba with a 400 in it and also a short block 440, which would be the better choice to build up? looking for around 500 horse-
thanks again!

 

[moparleo]

440 would be easier to build to that HP. How much do you want to spend and how long do you want it to last ? As long as the tab on the left rear of the trans that accepts the shift pivot bracket is there, it should be fine. Just compare the transmission where the linkage attaches.

 

[Chryco Psycho]

Well with the 400 you actually have a stronger block & can go to 451 CI easily or 480 ish CI with good reliability for street use
The 440 is ideal for 512 Ci , either will easily make 500 gross hp

 

[1973]

Thanks again for the info, the 400 is complete and running, don't know if that helps with cost or not, (for rebuild) - i did hear they could be built up nicer, but did not know if that was true--

is this tab on the trans something that bolts on or is it cast onto the trans?

i suppose 5 G in parts i was looking to spend, and would like it to last a long time- don't need to be doing that twice

 

[moparleo]

It is cast into the rear tailshaft housing on the bottom and has 2 holes drilled horizontally. That is what the slapstick shifters tail shaft bracket is attached to. The bracket has 2 studs pressed into the bracket that is mounted with nuts on the other side of the tailshaft housing.

 

[moparleo]

tail shaft bracket

is this tab on the trans something that bolts on or is it cast onto the trans?

View attachment 8256
Here is a picture of the bracket