[caseyjones]

Thanks guys. Some learnings about the front end spindle swap that might help someone else: This truck started as a 1964 GMC 1500 (3/4t). In 1964, the 3/4t trucks had lower a-arms that bolted to the crossmember, not the u-bolt style mount. That rules out a simple swap to 1/2t lower arms. The alternative was to swap to a newer 1/2t suspension, but I figured it would still need to be completely rebuilt plus I’d have to go through the extra expense and effort of installing the core suspension.
Also, CPP still lists two styles of conversion drop spindles but only the modular style is still available.