what is the min driveshaft angle you should have from trans to rear end that is the drive shaft it self Not pin angle can you run one almost level? this is a four link coil overs I seen in a post that some run them up toward the rear end meaning the trans is lower then the rear end what effect does this have never seen it before and how much higher can the trans shaft to center be

There is no minimum angle for a race car. Set it up dead flat if that is how everything fits together. Typically it doesn't work out that way but it all depends on tire size and oil pan depth and stuff like that. If you have really tall rear tires then the rear end gets pushed up in to the chassis. Sometimes the pinion centerline ends up above the transmission centerline so the driveshaft is running up hill.

On the front I try to set it at a 1/2* to 1*
on a four link.. anything but zero.. at zero
there isnt any movement to the U-joint

what happens if it runs up hill toward the rear end the trans being lower never seen this before does it cause a problem

Nothing.. just reverse all the numbers backwards
and it'll give you the same but it'll be opposite
of what your use to

It doesn't matter if it's at a side to side slope. The two U-joints have to have some angle to them. On a 4-link car get them at about two degrees.

Front engine rails are setup like that sometimes. You want the engine low so the driver can see and the driveshaft has to fit under the driver. The rearend is in the center of the tires so it can't move.

When you're building race cars you just do what you have to do....

Typically, on a backhalf, big tire, stock front clip car, the rear U-joint ends up being higher than the front joint, because the rear is substantially higher in the car than when the car was stock. Also typically on stock mounts, the engine/trans centerline is running downhill (towards the rear) about 3 degrees.

Pinion angle (or rear U-joint operating angle) on a drag car should always be negative,never positive. On this backhalf car example, this typically results in the pinion running downhill towards the front of the car. It also results in what is called a "broken back" configuration with the driveshaft being level or running slightly up towards the rear end.

I will usually try to move the rear of the trans some and work with the pinion angle to minimize the angles and the front to rear differences, but short of moving the engine, it's all just a compromise. Putting the engine where you want it fixes all of this.