7M-Brisbane : Firstly thanks for your reply, but why do you think it will be a bugger to convert to rear wheel drive. All you need is an adaptor bell housing to mate up to a W58 or similar etc, make some new engine mounts and the usual modifications for fitting a different motor and bolt her all up. I wasn't thinkin about using the original g/box and transfer case for a second.
I think I still will be able to get two turbo's in, but I will have to find out what size (eg T28 x 2) once I look at pistons/compression.
As to compression the standard compression ratio is 9.6:1, I still think this is a little high to be wacking boost into it or to much boost.