Hi Eric,
All spyders are mid-engined except the Perry which is built on a VW beetle chassis (and as with a beetle, is rear engined). Vintage, Beck, Thunder Ranch, Chamonix etc., are all mid-engined. Perry is the only maker left building these cars on a VW pan. The rest are tube frame.
You can use a 914 (901) style transaxle. The side-shift versions are alot easier to use in this application but even the rear shift version will work. You can use a 915 transaxle with a flipped ring and pinion and fabricated shift linkage. But it is somewhat larger and heavier than the 914/901 transaxle. It is a stronger transmission. Beetle transaxles are the most commonly used with the ring and pinion flipped for mid-engined use.
Go to the Photos section at the top of the page and peruse through. There should be several frame pictures or at least pictures of engine bays with the frames exposed.
Hope this helps.
angela
