I have got a suzuki sierra truck ( popularly known as maruti gypsy in india ).As I replaced the 1000cc gasoline engine of that truck with a 1800cc toyota 1C diesel engine whose weight is about 90 Kg. more than the previous one, I was faced with the problem of front suspension leaf springs going straightened and eventually broken. So I put an additional helper leaf in that. Now the previous problem is solved but the suspension has become very stiff due to which I can't run the truck on rough tracks. The solution which comes to my mind is either change the length of helper leaf or replace whole of the front suspension with coiled spring type suspension or make a combination of the two ( leaf spring and coiled ). Pleaz help me to come out of it and some way to make the suspension sensitive to ups and downs on the rough roads.Thanx in anticipation.