87 Patrol MK

Hi all, love the site. Came across it by accident and have since spent many enjoyable hours laughing at and learning about all things 4WD. My younger years were spent playing with Series 1 landrovers. Ok,you guessed it, Im no spring chicken. After 30 years marriage and mortgages the boss finally said yes to a 4WD. I got me a 87 MK Patrol P40 petrol 5 speed. A limo compared to the ol' landies. A quick visit to ARB soon had me thinking about remortgaging. I have two queries Im hoping learned members can help with. A: an easy and cost effective 2" suspension lift. B: Im running 31x10.5x15 tyres which are fine off road but on road the engine seems to be revving a bit high at 100kph. The engine redline is a little over 4000rpm and at 100kpm the the needle sits on 2800rpm. Is it just me being a little paranoid about blowing my baby. Any advice and tips would be very appreciated.