Hi d42tjim,
Not a good idea to run without the auxiliary spring and shackles for a couple of reasons:
1. The auxiliary or rebound spring and shackles is all that holds the front end of the tractor down and can be a serious safety issue if it were to raise up and over.
2. The auxiliary spring needs to be in place and tensioned right (although most are not functioning properly) to keep the equalizer spring in place so that it doesn't flop around and accelerate the wear on the oil pan mounting resulting in a cracked and broken oil pan. This is not a good design to begin with and needs all the help it can get.
The shackles can be made from flat bar and it would be a good time to replace the pins and bushings. If the mounting pad on the pan is to worn to provide aux. spring tension you can shim with brass stock.