I just installed my Gary Lewis designed , Tim Meyer of TMI ( 400 guru ) produced zf5 to 400 adapter . The adapter is a quality piece . Tim was able to sell me a freshly turned flywheel with the adapter . The recommended starter makes perfect contact with the ring gear and sounds great . I did not design or come up with any new ideas during this mod . Its already been covered by others who have done similar swaps with and without the adapter . I posted some pics in my gallery of the way I chose to "get it done".
I hope I can help the next guy with the following info:
if your truck does not have a "body lift " plan on unbolting the cab and placing some two by fours in between the cab and chassis while installing the ZF transmission . It's a very tight space .
You will have to cut and modify your transmission tunnel a little .
You will have to lengthen your rear driveshaft and shorten your front driveshaft as the ZF is approx 2 3/8 shorter than a 4x4 C6 transmission.
I highly recommend using the 1990 Ford hyd master and slave cyl for the clutch throw out arm . It's super easy to modify your pedal and install the master .
I don't know about using exhaust manifolds but I do know my regular "full length header on the passenger side did interfere with the starter motor . I opted for a set of Hedman fenderwell headers . They fit great .
Be sure to purchase the ZF motor plate with your trans , the starter is in a different location.
I am very happy with the outcome . These trucks are incredible when they have 5 (forward) speeds . http://www.tmeyerinc.com/SearchResults.asp?Search=Zf