73 Duster /6-318 swap

[Gabs927]

Hi FABO folk,

I have been reading through countless threads on here, and other forums, and each one ends in an argument regarding the need for a transmission swap when going from /6 to 318. People have said they did it without and others say it is not even possible. I am rebuilding my 318 and want to put it in my 73 Duster as soon as Im done, because here on the coast things rust FAST. But I need to know if I need to find a transmission really quick or not.

So I decided you guys on here would have the most knowledge out of anyone else on the web, and if you could clear it up one last time, I'd greatly appreciate it!

If I do need one, anyone know of a working or not working 904 transmission that needs a rebuild?

Thanks!

Gabs927
:newb:

 

[66340SEDAN]

Welcome, if you are swapping from a slanty six to a V8 you will have to swaps transmissions too, the bellhousing is different. The best route would be to find a V8 A904 trans.

 

[mcnoople]

Welcome, if you are swapping from a slanty six to a V8 you will have to swaps transmissions too, the bellhousing is different. The best route would be to find a V8 A904 trans.

+1

Different trans required. If it was a manual trans car you would need a new bellhousing but not a trans. With an automatic you definately without a doubt no question about it need a different trans. Luckily they made small block 904's for 20+ years.

 

[Bulldozer]

Hi FABO folk,

I have been reading through countless threads on here, and other forums, and each one ends in an argument regarding the need for a transmission swap when going from /6 to 318. People have said they did it without and others say it is not even possible. I am rebuilding my 318 and want to put it in my 73 Duster as soon as Im done, because here on the coast things rust FAST. But I need to know if I need to find a transmission really quick or not.

So I decided you guys on here would have the most knowledge out of anyone else on the web, and if you could clear it up one last time, I'd greatly appreciate it!

hmm, ive never read a thread here where anyone said that a slant 6 transmission will work on a V8. as these guys already stated , it wont. if you use a 904, you can use your driveshaft. it is an easy swap, i just did the same thing a while back with my 73 duster

 

[Gabs927]

Thank you everyone for the responses. I read on other mopar sites that you could. I'm glad I finally have a solid answer!
Much Appreciated!

 

[Vali68]

I think you may want to make sure you won't be burning up your rearend as well. the gearing maybe different with more power. So if your rearend is made to run from the Six, it may be over powered and burn your gears out.

 

[Bulldozer]

I think you may want to make sure you won't be burning up your rearend as well. the gearing maybe different with more power. So if your rearend is made to run from the Six, it may be over powered and burn your gears out.

99% of all gear ratios were used in all rearends in all applications across the board. im still using my factory 291 gears from the slant with the V8. the same gear ratios that were available with slants were available with V8 cars. there is no special slant six gear ratio.

 

[72bluNblu]

99% of all gear ratios were used in all rearends in all applications across the board. im still using my factory 291 gears from the slant with the V8. the same gear ratios that were available with slants were available with V8 cars. there is no special slant six gear ratio.

Absolutely, no special gear ratio's.

But a 7 1/4 rear end won't live long behind a strong V8. Maybe a little longer with an auto trans, but it won't take much thrashing on. It won't "burn the gears out", but it will definitely break something.

 

[Bulldozer]

Absolutely, no special gear ratio's.

But a 7 1/4 rear end won't live long behind a strong V8. Maybe a little longer with an auto trans, but it won't take much thrashing on. It won't "burn the gears out", but it will definitely break something.

i am holding my breath. so far so good. i am still using my 7 1/4 , 2 years running, and i will tell you its been tough treating it nice lol