New Driveshaft or cut mine to length - 904 SB to 727 BB swap

[68 Sport Satellite]

Hey guys -
So my '68 Sport Satellite has been a running car with a small block 360/904 trans from the time I bought it as I've been doing the resto-mod thing. 5 yrs and many upgrades later, the time has almost arrived to pull the 360 and drop in the 451/727. Should I pull my current driveshaft and have the local driveline shop modify it, or just buy a new one?

Current shaft is a 3.5" mild steel (larger than stock) with new (less than 1000 miles) Mark Williams slip yoke, new US Gear pinion yoke and new 1350 U-joints. If I modify this shaft as I planned on, it's just a matter of measuring the shorter length needed, then the shop does a cut, weld, and balance. Should save me money I'm thinking, but not sure. I think those Denny's driveshafts run like $900 complete. Car will likely not exceed 500hp since I'm running mild cam, iron heads and HP manifolds.

What say you? Looking for opinions on cost, criticality of the cut measurement accuracy, and 3.5" diameter vs stock for a 727 BB setup.

 

[Locomotion]

You'll probably save money in the long run if you shorten the existing shaft, despite the fact that you have to get a new slip yoke to fit the 727. Just pick a reputable shop. It will probably be easier to sell the 904 yoke rather than the whole shaft as well.

I don't have the difference in length, but try to maintain the same distance before the slip yoke bottoms out in the trans. It changes between ride height and suspension separation and I think ride height & lower has it in the furthest.

Personally, I've had excellent results from Spicer solid joints & a billet rear end yoke with U-bolts.

 

[68 Sport Satellite]

Good point on selling the 904 yoke separate.

My US Gear pinion yoke is billet with U-bolts and spicer joints. So good to go there. This 3.5" mild steel shaft I have in the car now was built by a local reputable shop - one of the first things I did when I bought this car since one of the u-joints was missing a strap. I've already talked to them about modifying the shaft when I swap the big block in. Just wondering if it will cost more or less than a new shaft.

Anyone else running a 3.5" mild steel shaft? I'm thinking keep this one and modify it.

You'll probably save money in the long run if you shorten the existing shaft, despite the fact that you have to get a new slip yoke to fit the 727. Just pick a reputable shop. It will probably be easier to sell the 904 yoke rather than the whole shaft as well.

I don't have the difference in length, but try to maintain the same distance before the slip yoke bottoms out in the trans. It changes between ride height and suspension separation and I think ride height & lower has it in the furthest.

Personally, I've had excellent results from Spicer solid joints & a billet rear end yoke with U-bolts.

 

[Rocketman]

Hey guys -
So my '68 Sport Satellite has been a running car with a small block 360/904 trans from the time I bought it as I've been doing the resto-mod thing. 5 yrs and many upgrades later, the time has almost arrived to pull the 360 and drop in the 451/727. Should I pull my current driveshaft and have the local driveline shop modify it, or just buy a new one?



Current shaft is a 3.5" mild steel (larger than stock) with new (less than 1000 miles) Mark Williams slip yoke, new US Gear pinion yoke and new 1350 U-joints. If I modify this shaft as I planned on, it's just a matter of measuring the shorter length needed, then the shop does a cut, weld, and balance. Should save me money I'm thinking, but not sure. I think those Denny's driveshafts run like $900 complete. Car will likely not exceed 500hp since I'm running mild cam, iron heads and HP manifolds.

What say you? Looking for opinions on cost, criticality of the cut measurement accuracy, and 3.5" diameter vs stock for a 727 BB setup.

I wish you were not so far away. I just had new steel put between my flanges for $163 cash and it is smooth. This guy builds drive shafts for all the racers around here but only accepts cash, no credit or checks.

 

[AMX364]

Had a shaft shortened by 1 inch ran under 100 total.

 

[Supershafts]

Have your shaft shortened, most all shops charge from 75 to 125 to shorten a shaft, which should include balancing.
Spending 900 with dennys and not using your local driveline shop which would do the same work and probably not be anywhere near that price is just insane.

 

[Meep-Meep]

There is a good driveline shop in San Leandro right off of Marina. Teagarden St. I think.

 

[Herr_Poopschitz]

Our local shop quoted $80 to shorten and balance mine...guy said aluminum was even same price as steel...