[Bored&Stroked]

The other thing to think about is to ponder what rear-end ratios would be the best - given your final over-drive ratio of the T5. Then things like rebuilding the brake systems, etc..

I've rebuilt/setup both banjo rears as well as 8" and 9" Ford stuff. One VERY nice thing about going to a later 8" Ford is the huge availability of gears, differentials, axles and brakes. Not only are almost all of the parts cheaper, but they're also available all over the place. Things like axles, bearings, wheel cylinders, brake drums, rear hubs, etc -- can get mighty pricey if you need to purchase them for your ole' banjo rear.

Ladder Bar Supports and Welding on Rear End Housings: Lots of folks will weld all sorts of brackets on rear end housings - but never check/re-align the housing alignment after the fact. When you weld things like spring hangers and ladder bar brackets on one-side of the housing, you'd be surprised how much the housing will "move/shrink" on the side you are welding on. Then imagine how far out of alignment your bearings/hubs are as a result. For this reason, when I am building an 8" or 9" rear, I start with either a wider one (assuming I'm going to shorten the width or a new housing unit without the bearing/brake flanges installed. After ALL the welding is done (and sometimes heating/shrinking for straightening) for things like ladder bars, spring hangers, caliper brackets, Panhard bars, etc. - THEN I use an alignment bar and weld in the bearing flanges on the outsides. And if I don't have the necessary alignment stuff - then I bring it to a shop that does and specializes in rear end custom work.

The reason I bring the whole welding/alignment issue up is because there are many shops that have the equipment to work on 8" and 9" housings to do the above work properly (alignment bars, bearing pucks, etc) - but try to find one that actually does this with early Ford banjo rears? Most guys just weld away . . . without thinking about how alignment issues can cause bearing, axle and hub issues on any rear end - let alone a banjo Ford.

If I was going to the trouble of converting to open drive, I'd seriously think through ALL the components I need - before making the decision. I'd probably go the 8" route unless I had a huge 'vintage/traditional' itch to scratch.

Best of luck . . . many ways to skin this cat!
B&S