series 1

hi
dunno if this is a silly question or not but
i currently have a series 1 86" wheelbase landrover
ive been offered a 88" wheelbase range rover chassis im wondering if the body is the same length or if the rear tub is longer on a 88"?
Also to make the series 1 body up to 90" length is it correct just to add the rear tub from a 90 to give the extra length or are the front wings longer on a 90?
any pictures would be helpfull
thanks

i have also thought about adding 90 front wings and rad panel, is this a direct replacement? also will this combination of series 1 doors and rear (86") fit a 90" chassis?