Brians1

oldcutlass

I had one made here in the DFW area. You may be able to get one made local to you.

monzaz

Most Truck drive line shops can make any drive shaft you need.

Jim

Brians1

oldcutlass

I supplied the yoke and mine was under $300 with Ujoints.

Brians1

VC455

When I had a locally-built driveshaft made, there was no communication on options for torque capacity and drive line speed limit. They just made a shaft with about the same specs as factory. This was for a 1970 442.

When I did the mechanical work on my Vista Cruiser, I called Denny's Driveshafts. I actually spoke to Denny, who gave me a great education on the interplay of diameter, length, and weight of shaft and how they relate to torque capacity and speed rating. I had options for U-joint capacity as well.

Because of the length of the shaft and limitation on diameter in the stock tunnel, I needed a lighter weight 3.5" shaft.

My experience showed me the value of a specialist firm in helping you if you consider your application to be different from factory.

Run to Rund

The yoke spline area to u joint varies with brand. OEM Saginaws are around 1.5" iirc, and Spicer more like 2". That will affect the length needed. Mark Williams Masterline series is a good choice if Spicer 1350 joints are OK with you. They would require a new differential companion flange, but aftermarket flanges can be a lot stronger than the OEM. If you will really have that much HP, you want a lot of strength for insurance. Also you will want a driveshaft loop, solidly mounted to the floor at a reinforced area.

MW also has a chart on line with critical speed vs. material and length of the driveshaft. You will probably want 4" aluminum to get adequate critical speed value.

Brians1

Thank you !

droldsmorland

Dennys...

http://www.dennysdriveshaft.com/

Click on the how to measure tab for that info.

Be aware your e brake forward cable will interfere with a non stock shaft. I haven't reworked a viable fix for mine yet.

allyolds68

http://fleetpride.com/

I supplied a stock driveshaft and told them what I wanted for center to center (I used the Denny's website referenced above). They charged me a little over $100 to cut down, weld, and balance the driveshaft I supplied

My442

Need to be careful of the local truck shops, as most of them don't have the hi speed balancing equipment.

I used Thrash Driveshaft in Texas. They did a great job.

Run to Rund

Stock quality tubing, ends, and yoke are OK for near stock HP. For 550 HP I would not want to trust stock stuff. When you are going through the traps at 120+ mph and 6500+ driveshaft/engine rpm, you want the best.

droldsmorland

I dont know Mike. Normally I would agree but I just had the main driveshaft in the 250 balanced and rejointed by Fleet Pride and it definitely wasn't up to par at all. The over centered both joints which caused a vibration. I took it back and they whacked the cups with a hammer and handed it back to me. Im all done there. I found Cook Brothers truck parts off Mt Read Blvd/Driving Park area here. The parts guy and I know each other from my Delphi days. They surfaced my flywheel and rebuilt the main and half shafts in the 68 Vette. I watched him do this work. They know what they are doing. Dennys is top notch as well. He did an aluminum shaft for the 442. Its a piece of art. But I dug deep for that one. Not all Fleet Prides are created equal buyer beware.

droldsmorland

Agreed, thus the need for a Dennys Shaft. He makes stock shafts too.

VC455

Perhaps there was something unique about my 6-speed install, but I couldn't fit a 4" through my driveshaft tunnel with the rear axle on the bump stops. I made sure I had the factory engine-transmission angle too.

Denny said I needed a 3.5 metal matrix composite shaft to get the strength and critical speed value. If a 4" would have fit, the construction would have been just as you described.

My driveshaft speed was high because of the 4.10 rear axle ratio. The extended wheelbase required a very light and stiff driveshaft.

Even with the 3.5" shaft I had to heat the smallest area of the driveshaft tunnel and use a 4" pipe on a jack under the hot sheet metal to recontour that area. (The area is about a foot aft of where the attached picture ends.)

Brians1