I am using a 2004R in my 67. I think I need to change the driveshaft as I had a 300 before. Besides I really don't think using my 57 year old 2 piece driveshaft is a great idea. My local drive shaft shop closed. So the nearest shop that does custom driveshafts for cars is 2 hours away. I looked at Denny's and Empire and they talk about limiting their drive shafts to 400 HP. Some will go to 500 HP. Not that I am going that high, but what do the 600 HP+ guys do? Also, choosing between diameter, material (steel vs aluminium (not considering composite), slip yoke and u joints. I want to keep the stock rear end carrier. I need some advice! Help!
The 200-4R is very close to the Turbo 350, which I thought was the same as the ST-300 length. I'm all for getting rid of the 2-piece drive shaft. Your current drive shaft length should be workable. The 200-4R is only 1/8" longer than a 350, so, taking 1/8" off the current length would be what you'd need. I'm using a factory 350 turbo drive shaft out of a 72 GS in my 200-4R behind my mild Stage 1 455. I'm not going to the track so I suspect it will live for a very long time without traction. Here's the specs I found.
Contact Bob. He has done half a dozen drive shafts for me. Great to deal with and very fast. I used DOM tubes and 1350 and/or 3M Spicer non-greaseable joints. Bob Guzman Action Machine Inc. 1847 Prairie Ave South Bend, IN 46613 (574) 287-9650 www.actionmachineinc.com https://www.facebook.com/action.machine.inc
Critical speed on both my '64and '68 driveshafts are 6800 RPM. With Overdrive it would be 6000 RPM. So, at shaft critical speed, I'll be doing 277 MPH. I'll be... fine.
Overdrive transmissions only lower engine rpm. Driveshaft rpm is dictated by road speed and axle gearing.
Yep. 6800 RPM shaft speed is the critical speed, that's 6000 engine RPM with .68 overdrive for my car with my gearing and tires.
I had a driveshaft go on me at 112 mph at the top. Regular steel driveshaft came apart in four pieces and took out everything from the rear end all the way forward and the floor. I looked to Mark Williams Inc. for a replacement ended up with a chrome Moly with larger diameter so critical speed would exceeded my horsepower and RPM. Evaluate your true needs. It’s worth the extra cost for the safety a strong driveshaft to provide.
3.73, but, it was more than just that I was running a short shaft turbo 400 and with a station wagon the driveshaft stretched out to about 57 inches. I don’t remember the exact size but if the driveshaft was 2 1/2 to 3 inches critical speed was way down in the 5500 RPM range for the length of the driveshaft in the material it’s made up, which is why I went to such a severe duty driveshaft. Along with the better driveshaft, I also went to a long shaft turbo 400 which shortened everything up by about 4 1/2 -5 inches. So in essence my critical speed is well above 7500 right now which is way more than enough.
Looks like shorter Drive Shafts have higher critical speed. My GV driveshaft is 14.5" shorter than stock. From https://www.markwilliams.com/driveshafttech.html
If you are driving that wagon at the track...it is possible that you just tweak the the shaft on a hard launch enough to put it out of round and then hell broke loose at top end. IT IS RACING so anything and everything will happen. Might have just been crap luck. I took a stock MONZA 2.5" or less shaft to 10.90 for 4-5 years ..nothing ever happened to it. still have it for a spare. NOW remember that is a much lighter car...BUT torque and hook is torque and hook fronts up a foot all the time.
