My Biscayne will have a healthy 496 BBC installed shortly. It is currently running a smallblock with a Muncie and 12 bolt rear. I has 1330 series U-joints in it now. I am wondering if I need to upgrade to 1350s because of the increased torque of the new engine. This is going to be a street car that will likely never run slicks or be dragged but I'm sure there will be opportunities to lay into it .
If it's out, upgrade it. Going through that now on my truck, trans went out. I knew i should have replaced it last winter when the new motor went in. Since its on the lift a new rear end is going in also. I hate doing things twice.
I ran 1330s on my 55 for years, with a blown big block. Doesn't launch very hard, though. If you're keeping the 4 speed, you probably want to upgrade the driveshaft. Or just drive it and find the weak link.
In what car, length and tube diameter (3" or 3.5") are relative as is critical speed of driveshaft (Maximum rpm determined by length). How much HP and type of U-joints (1310, 1330 or 1350), steel, alloy or composite, transmission and rear end. 1310 are good for up to 500hp; 1330 are good for up to 700hp; and 1350 700hp+hp with maximum length of 35"; These are centre to centre of U-joints:- 1310 steel (2") for up to 500hp with maximum length of 35"; 1310 steel (3") is good for up to 500hp with maximum length of 55"; and 1310 steel (3.5") is good for up to 500hp with maximum length of 63". Are you using greaseable or solid U-joints? 1310 is 3.219" (3 7/32") wide in both directions across bearing caps with 1.062" (1 1/16") diameter; 1330 is 3.625" (3 5/8") wide in both directions across bearing caps with 1.062" (1 1/16") diameter; and 1350 is 3.625" (3 5/8") wide in both directions across bearing caps with 1.187" (1 3/16") diameter.
I'd be asking questions like "how often do you launch off the trans brake" and "what is the clutch lining material"
You didn't say what year Biscayne but if it has the center support bearing you may want to upgrade it. The "X" frame Chevys are Flexi Flyers and the frame is easy to twist when you go to BBC power.