I picked up an 03 4x4 ECSB a few weeks back and have since started "making it my own". I've picked up every part I need to complete the 4l80e swap I have planned. Only thing I don't have is a new rear driveshaft.

My original plans were to turbo the truck and make around 500-550whp. But for now, I believe I'm going to stay N/A for the remainder of the year atleast. Simple cam and a decent set of heads and call it a day.

After the 4l80e swap, I only want to dick with the rear drive shaft once...so here is my question....

What are these factory aluminum shafts good for as far as speed and HP? I have been told you absolutely can not spin them more than 100mph, and I have also been told guys are trapping 130+mph with them no problem.

If I can just have mine shortened, that would be nice, if not, then I'd like to know what people have experienced. Buying a quality $500+/- drive shaft is not an issue, but if it is not needed, then sweet.

 

I would get a good one, the stock shafts are about the thickness of a pop can. If you have to get one shortened then just buy a quality aftermarket one and be done.

 

I can tell it is very thin by tapping on it. Only reason I was questioning what it could handle is because the stock aluminum shafts in the CCSB duramax trucks will handle over 1000whp and all the torque that comes with. I made over 1100whp and 1800+ torque in mine with a stock shaft and those feel paper thin as well. But those are also 5" diameter.

I'll play it safe and have one built.

That brings up another question though. Will I run in to issues using factory size u-joints at 500-600hp? I ran stock 1410 u-joints in my duramax and even at 1200whp and 2000+ torque, I never once broke one. I see guys upgrade to the 1350 series, is that actually needed?

The front drive shaft for my swap is an OEM front shaft from a duramax/allison truck so I already know those are plenty strong since I still had a stock front drive shaft in mine, even at 1200whp. I want those say those have 1350 u-joints in them. That was even in a full weight 7000lb crew cab that trapped 135mph.

 

Anyone else have some insight?

 

Basically what was stated above. They blow apart and it's not pretty when they do... Its been documented many times.

A D-max is a different animal. Those shaft give you more surface area. I believe there also slightly thicker albeit not much though...

 

Noted, new shaft it is.

 

Ended up having this monster built. I asked for 4" .125 wall with 1350 u-joints. Some how they ended up building me this 5" .125 wall shaft with 1350 u-joints. Oh well I guess, works just fine and was the same price. $460 including tax. I guess if I ever end up making 2000hp, I'll atleast be covered lol

 

Nice. Who built it?

 

Six states distributors here in Salt Lake.