DSS 3.5 vs 4.0" DriveShaft

So I kinda rushed buying a used DS, not realizing there were both 3.5" and 4.0" driveshafts made by DSS. I don't see the 4" for sale really anywhere, was there a legit changeover or discontinuation of the 4" ones? major power difference handling between the two?

Apparently 4" basically MAY transmit less NVH. Don't worry about it...

Thanks, but that just confuses me more. If 4" produced less NVH, why was it discontinued?

And surely there must be a power handling decrease going from 4" to 3.5" OD tubing, no?

Because 3.5" fits better and is easier to install (the shaft won't get in the way of your socket/extension for torquing), it's a more standardized shaft size and strong enough. Various reasons... it may be a little lighter, too.

I have the 4" with 0 issues.