Howdy!

I broke a stock 7260 727 slip yoke and took out my trans so I am stepping up to forged steel 1350 yokes and solid joints.

My driveshaft is short- around 39” U to U and my rear is a 3.21 gear so I probably won’t have to deal with having to stiffen up a long driveshaft or approaching critical or resonant rpm with it. I just want to make sure that I don’t make the shaft a failure point otherwise there’s no point in the beefed up yokes & U’s. It’s a hot street car application- approx 600tq 450hp and 5500 redline- way over stock but nothing crazy compared to a lot of folks around here! I’m not really looking at aluminum and certainly not CF.

My local driveshaft shop (Pete’s welding in Trenton NJ) says 3” by .083” dom is their go-to for hotrods but they can do 3.5”. I’m thinking the 3.5x.083 would be bulletproof for my setup?

While I am in the race section begging driveline advice- what’s the weak point for me now? I have a solid flexplate, fresh 727, steel yokes, 9.25 with a healthy 3.21 sure grip blueprinted with new upgraded yukon axles. I know the C-clip rear can be dicey but I jave jeep ZJ disc brakes on my 9.25 so if I did lose a c-clip I’d have time to pull over before losing a tire/wheel tub.

Also I am confused about proper street driving with the 727. I understand that breakaway low in D is 1st with no low band apply so the sprag is vulnerable. So if I’m going to do a rolling smokeshow starting with flashing the converter against the brake I should be in manual second? Or is manual 1 ok as long as I shift into 2 quickly and don’t pedal it?

I like cruising in Drive and one of the great joys of a hotrod is not only laying stripes at will with a little extra throttle but knowing how to just chirp off the line without really losing traction. Should I be more careful with breakaway low and only use Drive for relaxed cruising? Then if I end up shifting manually (tf2 kit) whenever I’m alone and playing with mustangs & camaros do I need to be careful with manual 1st or just pay attention to not pedal it and get back in hard hammering the sprag?

I’m probably overthinking it but my rear summer tires are getting shorter pretty quickly and I want to step up to M&H DOT drag radials and maybe try to run a low 12 in this pig before summer is over.

Thanks!