I take it your going carbon fiber since the chart doesnt go to the length you want?

Nooo!lol That leaves 2 other options ms and aluminum

in this link an aluminum 4" can take 2k hp and this is what Mark williams wanted to sell me 1st at my length so at 1/2 the $ of cf this works for me even with shipping 50$ maybe. aluminum ds spec from the link"Description
3.5″ Shaft with, 1350 Series “Gold” Cryo treated Solid U-joints, are built under the most Stringent Tolerances in the industry. Tubing is Factory Straightened to .010″ total runout at the center of the tube. Tube yokes are welded to within .006″ runout on each end. The shafts are Electronically Computer Balanced to less than 1/8 Oz/Inch, as an assembly, assuring smooth operation at the Big end as well out of the hole.

Critical Speed is calculated on each shaft to insure your Safety and Ultimate Shaft longevity. We recommend the 3.5″ shaft in most cases to 1000 Horse Power. 4″ Shafts are recommended to 2000 Horse Power.

Shafts are complete with the most common standard transmission Slip Yokes. In some cases an upgrade on the Slip Yoke or U- joints may be considered."

How about chromemoly DOM 3.5 tubes?

In the chart the rpm limit is much lower for cm.My driveshaft speed would be 6300 I think at 140 mph.I have some hard choices to make here it looks like so I need to revisit the data

So I would have a ds speed of 6266 with a mph 140 and a 28" tire and 5848 with a tire of 30" so with a 30" tire I think a aluminum 59" shaft is doable.Or even a 4" mild steel

Did you use this calculation for the ds speed?
Top speed x 336 (a constant) x rear ratio (like 4.10), then divide it by the tire height (28” tall tire)
It doesnt look like it

yes I did w 3.73 gear so 140 mph 3.73, 30" tire

I got the driveshaft today so just waiting on the PTC 4500 stall 9.5: vert.The ds clears thew hoop plenty and the ds was 663$.I am also waiting on the shifter sideplates to go to a th400 and it should be here today or tomorrow.I will sell the 727 sideplates.

I will be getting my 9.5" vert from PTC today to complete what I need to get running again so I will be back to work for a few weeks on the car.I don't expect to get to the track this yr but will run on the street to test the carb jetting that have been sitting on the blower for 3yrs or so.I will post a video I hope when I drive it.

Are you going to put the blower back on it for the street duty?

yes!Low boost 5 to 8 lbs and that would be 3 or 5%OD

Looking forward to when you finally get it back to the track

Thank you Me too!There is no good in having a blower if you can't use it.I will not use the intercooler for now also but when I get to the track I should have it in and plumbed.

Just some GM style converter picsI measured the pilot fo fit the flexplate adapter 1.702 pilot and 1.704 adaptor hole.I need to put the fplate agains the vert to check the bolt holes.I got 3 bolts,nuts in the box with the vert.[7/16" maybe]I will check the crank bolt to fplate gap also.When I unbolt the trans I will check the installed ht in the bell

some update pics.I had to put a friend in his final resting place so getting to work on this was slow.Lokar dipstick fits nice.The vert went in clean. 1.22 to the mount pads, .900 to the pilot from the bell face.I need to measure the pad to fp gap yet and pull the vert to the fp.Now I will be steady at work on it.ty for reading.

sorry for your loss .

looking at the filler , could you have dented the floor away a little and run a solid tube ?
lots of hard work youve covered thanks

Tex

I think you could make a solid tube work but why dent the floor when you can form the tube?.My Lokar is about 34" long

Thank you for your sympathy for Cpl E-4 USMC Brian King

Condolences on your loss.