Driveshaft Swap

[Doode]

Hello Folks, I dropped a built 440 and 727 into my 1979 Cordoba which means the 8 1/4 has to go and I am replacing it with a 8 3/4. Current 50 inch driveshaft original to the former 360/904/8 1/4 fits fine but I will need the 3.25 inch diameter to handle the extra torque, is there a swap I can do? Are the u joints the same? Thanks, Doode

 

[66Satellite47]

My advice, buy a new stout driveshaft. In 1975 I used a stock '66 shaft in my '65 Coronet with the 426 Street Wedge, it exploded at 110 MPH in the traps, disintegrated the 727, cute slices in the floor pan. My current Satellite got a new stout shaft soon as I bought it. IMHO never skimp on a driveshaft.

 

[33 IMP]

I snagged a 26" radiator from a 75 (?) Cordoba with a 400/727 combo. It probably had a 9 1/4 though, i dont know if that would work , or where to find one.
66satellite47s advice is really good. A cheap, not-quite-right shaft is not a good risk.

 

[66Satellite47]

Not just if it's not quite right, if the shaft is a bit old (worn) & wasn't originally designed for big torque & power bad things can happen.

 

[Mopar4Speed]

Have you considered getting one custom made? Tons of driveline shops can do it for you and have it done right the first time. Could even upgrade to an aluminum so it will be more stable at higher rpms/speed. Just me opinion.

 

[Doode]

believe I will have a custom driveshaft made...