Better Shifting Mopars

Have any of you boys heard of this trick? A local guy who does a lot of racing 4-sp building/repairs has several tricks to get Mopars to shift better. I know from personal experience that thinner oil really helps with no negative effects on wear if you use the right oil. The modification that caught my attention was the conversion to GM syncros and their locking pins. Some other mods were to the syncros themselves and the cones they ride on. Steel shift forks over the original brass. I love my Mopars but they have the worst shifting 4-sp. These 4-sp can shift better.