71 Dodge Dart 273 swap to 318

[Kardon1976]

I am getting close to putting in the new 318 engine and I have a torqueflite 727 transmission (long shaft). My question is, do I need to get a longer/shorter drive shaft to connect tranny to rearend? Any and all help welcomed


Thanks FABO members.

 

[krazykuda]

Nope, yank out the 273, put all the dress up on the 318 and toss it in. Direct bolt in replacement....

 

[krazykuda]

If both the 273 and 318 are running a 904 trans, you will be fine....

 

[Kardon1976]

OMG I appologize FABO members I meant to say that this is the origional inline 6 in the car now NOT the 273. Do I need to get a longer/shorter drive shaft to connect tranny to rearend?

 

[diymirage]

if you insist on running the 727 the yes, you will need to have the stock drive shaft shortened and rebalanced
(or have a whole new one build)

now, if you want to keep the 904 you could get a V8 belhousing for it and call it good

 

[Kardon1976]

Thank you DIYMIRAGE for this info.

Do they make a drive shaft that I can buy and install or do I have to have it cut and balanced.

Another question I have is, do I have to change out the rear end or can I keep the one that is there with the new 318 motor?

 

[krazykuda]

Thank you DIYMIRAGE for this info.

Do they make a drive shaft that I can buy and install or do I have to have it cut and balanced.

Another question I have is, do I have to change out the rear end or can I keep the one that is there with the new 318 motor?

Some drive shaft shops can make you one from scratch. Tell them the length and what U-joints to use and they can make one up if you want to keep the original....

 

[diymirage]

once you have the 727 installed you have two options
measure the distance from the tranny to the rear end and have your stock unit shortened and rebalanced or measure it and have one made to spec
there are several list floating around with what size driveshafts people have and there are just too many variables to have one made before the motor and tranny are in

not everyone agree on the strength (or weakness) of the 7.25 rear end but most of us will agree it will hold up to the power of a 318

I wouldn't bother messing with it unless it broke

 

[BlueDream]

if you insist on running the 727 the yes, you will need to have the stock drive shaft shortened and rebalanced
(or have a whole new one build)

now, if you want to keep the 904 you could get a V8 belhousing for it and call it good

A slant six auto trans won't work on a small block. Manual trans will if you swap the bellhousing but autos have a one piece case. Right?

 

[Infecteddog]

A slant six auto trans won't work on a small block. Manual trans will if you swap the bellhousing but autos have a one piece case. Right?

Yes, correct. 4 bells- AMC, Slant, LA, and RB.

You can buy a driveshaft- it'll probably about 3x what having yours cut/balanced will be.