Morris Minor Owners Club

I have a saloon that has had an anti-roll bar fitted to the front. I want to add telescopic shocks to the rear. It will mostly be driven around town and I find the present ride pretty good but need to reduce axle tramp and give a bit more resistance for those numerous potholes and speedhumps. What would be the better option, gas or oil shocks?
TIA

Lo I am running a front roll bar with oil filled (uprated Mini) rear
dampers and experience no wheel tramping,with a standard
1098 engine. I believe that gas shocks are more efficient though
slightly more expensive. I assume you are already on radials.