The Aero Racing TB kit fitted to my 4/4 Sport included a 4.1 diff in place of the 3.7 fitted as standard and it made 5th gear much more useable than an overdrive. The 4.1 was definitely noisier than the standard diff. but that was the only problem. Billy Bellinger at "www.jb-engineering.co.uk" might be worth a try.
Last edited by Max5; 08/04/20 02:17 PM.
