Ronnie, personally I would stay with one flex coupling. Also for gear drive models I would use solid engine mounts and an old style 3 pin driver. In my experience, QuietLine gear drive tractors are particularly sensitive to correct shaft alignment due to the ISO mounts. Clutch vibration can occur and it is very annoying! Make sure the bushing in the drive plate and input shaft adapter and bushing on transmission are tight (no wobble). Also make sure the drive shaft is not worn at clutch release bearing area and clutch release arm is not worn at pivot area. Have fun!
