A fellow PPC forum member has a diesel type to sell, thought it may be of use to someone on here.
http://www.ppcmag.co.uk/forum/viewtopic.php?f=2&t=7452

Punt it on the stock car boys they use the ones from the p100 as the ratio is perfect for their circuits.

Ive got one here as well...that needs a home

were the ratios any better, or was first gear worse for a light car?