Fire Wall.
I think you will find that for this configuration the factory location on the fire-wall will be the easiest and most liked spot. We started out with an E.C.I. IOX-360 with a Prince carbon "P" tip prop on it and the E.C.I. tapered "C" cylinders.
This made our engine as light as we wanted with a little extra power. We really wanted to have two batteries split by a Blue Water switch as a master. We first installed the batteries at the rear factory location and put the master on the right kick panel. This was a very good set-up and we liked it, BUT. Once we got the aircraft ready for fight testing and weighed it, we found that we lost full use of our rear baggage capacity. We wanted to be able to use this platform to its fullest potential so we went back and pulled all the rear battery installation and placed a single PC-680 on the fire-wall, just as the plans show. We now can load all 50 Lbs. in the front baggage, full fuel- 252 Lbs., 195 Lbs. in the front seat, 185 Lbs. in the back seat, 50 Lbs. in the rear baggage floor area and 25 Lbs. on the rear baggage shelf, with plenty of room to spare. We ended up at 1008 Lbs. empty, with 792 Lbs. useable. This can give us two 200 pounders in the seats and full fuel to go wear we want and still give us full baggage. Oh and by the way with this power to weight ratio, when you are running light and want to have fun, it makes for a "nice ride".
Just what we did, its your ride and your type of flying that counts on this one. Yours, R.E.A. III #80888