Here's an interesting idea I've pursued lately. I'm looking into putting a Mendeola SDR5 into the Pantera. It's a transaxle developed specifically for the kit car world, and it is similar in size to the ZF but slightly longer. It weighs 14 lbs more than the ZF in full dress at 168 lbs with bellhousing, but that includes slave cylinder, etc. In all, it might be 10 lbs heavier.