cheers for that .. I must have picked up wrong because he would deffo know the score on that. Your comment made me do some reading up on the sudject and your spot on. However im still lost as to why the diff has this ratio ! Im planning on type 9 gear box and a cossie spec engine around 250 bhp. Whats your thoughts pls and who or why fit a 2.1 diff ratio ( defo 2.1) cheers Ronnie