[jonmachota78]

Ok, I've done a bunch of searches an I'm not finding much info. I'm building up my 8.5" 10 bolt, the whole bit, 1350 yokes included, so I understand I need to shorten my driveshaft because the 1350's are a bit longer than the stock 1310's.. Soooo, I'm assuming it's a good idea to replace the stock shaft rather than shortening it. Please correct me if this incorrect, I'm not opposed to retaining the stock shaft if it would be strong enough...

Where do I go or who makes custom length drive shafts? chromoly? aluminium? Other 'affordable' options? Pros-cons? I think I remember reading to measure from the center of the u-joint to center u-joint, and that's the measurement use to make a new shaft.

Any info about this would be appreciated! Jon

[67drake]

Depends on what you are doing with the car and your power output,but cutting your original should be fine if it's in decent shape.
I can have one shortened for $150-175,or a new one made for about $200 around here.

[jonmachota78]

some info in my sig. I expect 550+ hp after the cam swap I'm planning. mostly street use BUT I will be taking it to the track with drag radials. My goals are mid 11's. Stock/shortened shaft up to that?

[67drake]

Sorry,I didn't know if it was a stock type set up or not. What the cut off is for going stronger ...I don't know. I'm sure somebody will chime in.

[Pontirag]

save the stock set up as the supply is finite. make a new one and gow with thicker wall tubing. it does not cost that much more and is safer meaning the other parts will survive too and that cost less in the long run.

[jonmachota78]

who sells the shafts with the thicker tubing?

[PontiacMatt72]

I'm gonna chime in with a relating question...

I'm going to get a new driveshaft made this coming week. to keep it simple, lets just say I am making the same power (550ish hp/550 lb.ft. roughly) (not quite, but not too far off).

What is a good size diameter, tubing thickness, and material for a driveshift at this power level and for "abuse" at the track?

[myckee]

I'm making around the same power as you and I went with a Denny's "Nitrous Ready" driveshaft. It has a lifetime warranty against breakage, and wasn't much more than their HD shaft.

http://www.dennysdriveshaft.com/c1_n...iveshafts.html

[jonmachota78]

Originally Posted by myckee

I'm making around the same power as you and I went with a Denny's "Nitrous Ready" driveshaft. It has a lifetime warranty against breakage, and wasn't much more than their HD shaft.

http://www.dennysdriveshaft.com/c1_n...iveshafts.html

thanks, myckee, that's exactly what I'm looking for! Did you 'get the shaft' yet? Can you give us a report? How do you like it? Customer service? How long did it take to get your order?

Any other reputable outfits out there that do driveshafts? -jon

[Ron Genovese]

Strange did a few chromolly shafts for me. Quality is excellent and fast turnaround, about a week. I checked with Dennys, but they take too long to get it to you.

[myckee]

Originally Posted by jonmachota78

thanks, myckee, that's exactly what I'm looking for! Did you 'get the shaft' yet? Can you give us a report? How do you like it? Customer service? How long did it take to get your order?

Any other reputable outfits out there that do driveshafts? -jon

I actually bought my shaft from them a few years back. They were very helpful on the phone when I spoke to them regarding how to measure for the shaft, and which one to get. I placed my order and and the shaft was built (each and every shaft is custom built, no one size for all firebirds etc) and shipped in the timeframe they had told me. It was packaged well and fit in perfectly. I have no complaints at all.

[TheMonkey]

with new rear end yoke going to 1350 from 1310... do you actually need a shorter driveshaft? does the yoke actually stick out from rear end further?

seems like driveshaft would stay same length, but just require a 1350 end on it. so, if your rear end of shaft goes to 1350, that effort is not worth much unless you swap the trans yoke up to 1350 also which pretty much means totally new driveshaft anyway instead of just modifying existing.

i just talked to Dennys a couple days ago... they have 4 week wait. if you have to wait for it and the yoke isn't any longer, just put a conversion 1350/1310 u joint on to enjoy the car in the meantime.

[Socrates]

The 1350 Yokes are a good 3/4" longer then the 1310/1330 yokes on a 10 or 12 bolt rear.

Find your local driveshaft shop where all the local drag racers get D-shafts made, likely a heavy duty trucking machine shop, and have the same shaft made for half the price of Denny's and 1/20th the time to have it in your hands. Don't use the original tube, go stronger at your power level, especially if you expect traction. You can sell your original D-shaft to help offset the cost of the new one.

For d-shaft size at your power level, go 3.5" minimum diameter, 4" if it will fit (not likely), and aluminum or mild steel is your choice, though your gearing will be an important factor deciding all of this due to the critical speed of the driveshaft. The D-shaft critical speed is the point where the metal becomes unstable, where the rapidly spinning tube goes from straight to rippled due to reaching its natural harmonic, which ultimately explodes/snaps the shaft. I rationalized it was better to use 3.5" mild steel at the long length of the shaft needed for my 66 GTO with the 4.56 gears and 0.5 overdrive, as the shaft will be spinning at ludicrious speeds in 6th on the highway. A 4" tube wasn't going to fit for me, or esle I would have used aluminum at 4". Ultimately talk to your builder for the material type and size, as your driveshaft guy does this for a living will likely give you the straight scoop.

You can use this chart below to make sure you keep within the material limits of the shaft you choose base on shaft speed, length and material type.

http://www.markwilliams.com/driveshafttech.aspx
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