You can fab one yourself by using the 4 mount points for the engine mount. Use angle iron
connecting the top and bottom points horozontally. A verticle piece on center of these will locate the pivot point. From this use a auto engine stand to provide the pivot and support for the fwd point. The aft support I used was angle on the extended (before trimming) side skin aft of the rearmost bulkhead with a plate connecting them. a bolt with bushing thru the pivot point of the plate to another auto eng. stand.
Walt RV-6A
IO-320 CS finishing up
 
See if these pictures help

Ernie,

I made this rotisserie using a Harbor Freight engine stand and 1/4" aluminum brackets two inches wide. I drilled them to the engine mount holes and then to the cross-bars and the stand. I made this copying some other stands I found thru the archives. I used it on my -6QB fuselage.





I have a few more pictures on my photos website. Look at the Feb, 2008, album.