odxr

I am building a 1957 Chevy 210 for a customer.I got a bracket kit to install an early c4 rear suspension assembly on the frame.I scored a 1985 4+3 car to get the d44 diff.Power will be a ls6/t56 with an A&A blower out of a 2004 zo6.I know I can get some good spicer ujoints because the rock crawler shop next door stocks them.My question-how much can the aluminum shaft take?The car should weigh about 3300 when done.Going to go to a 3.73 axle ratio.

Nowhere Man

Your tires have more to do with it then any thing. You can have all the power in the world. If you can't get it to the ground it's useless. Running street tires I would think you will be fine. Start running real sticky race slicks you might have a problem

Tom400CFI

about the street tires. They act like a "fuse", spinning before breakage.

Rcklessdriver has put 700+ hp through the IRS for quite a long time, 60'ing in the 1.3 second range. So the shafts are pretty strong. It was he, who pointed out something pretty profound; when running at the limit, like he was, he felt that extended bump stops that prevent the suspension from going into compression/jounce, or preventing the axles/unjoints from having to have any angle in them, helps. He's right; if the u-joint has any angle to it, you get angular acceleration/deceleration twice per shaft rotation. That is going to add a lot of force through those components.

SO...street tire and controlling suspension travel are a couple things to think about.

Paul Workman

Several of the local stroker/sleeved ZR-1s with 600 to 700+ hp at the crank seem to show the next "Achilles heel" to be the stock spindles; not the half-shafts. (But, with enough torque, even they have their limits, of course.)

Upgrading to either a 31 spline or a 33 spline spindle/hub appears to be the solution to stock spindles being twisted off.

(Shown are 33 spline spindles on either side of the stock splined unit (that is re-welded to show the differences...)



For a "plug and play" option, the 31 spline spindle and hub broaching, I can refer you to Mark Williams Enterprise.

pologreen1

If street driven they are fine. U-joints give out first. My rear has seen 650-700hp for years now and at the track on DR's.