Don`t forget to get the valve seats done, I have a six pot Land Rover and have just fitted an electronic distributer from Power Spark, it was £100 including coil and leads and it goes very very well, they do do a change over box that alters the timing for petrol and gas, it runs a little retarded on petrol, but at £180 extra I did not buy it, as I start on petrol and as soon as I can I change over to gas. :-)