Tom Woods is good. Make sure you get the correct diameter tube to clear the transmission.
Got front and rear after my 4r70 swap with 3.5 SL great quality
That's a great question. I don't know how many choices there are in shaft diameter overall, but we carry two sizes in stock.
Our Level-1 shafts would be similar in diameter to the stock shafts, while the Extreme shafts use a smaller diameter, thicker wall tubing.
And in all these years, this discussion has served to point out the fact that I never checked them!%):-[
Let me see if I can get a quick answer that we can compare to what spap says when he reports back.
Paul