Joe,
I am going with the BGH 5 speed from Caterham USA. I do believe the box I'll be getting is the E6 box from the chart on this page
http://hometown.aol.com/dvandrews/bghpage.htm
but have sent an email to confirm.
The choice of gearbox and rear end ration was a hard one for me but I ended up with a 3.92 rear for my Superlight R with Zetec SVT engine of about 185 HP. From what I can tell, the Zetec and Duratec have a broad torque range for which the 5 speed may be better than a 6 sp. Caterham USA's 25 hr. racecar used a 5 speed and the SVT engine.
Have you sat in the cloth seats? I find that they don't fit my body (too much curve on the backs) while others seem happy with them. I like the Tillots and will be getting them.
Give Caterham USA a call and they should be able to help you with your questions about the tires, radiator, etc.
Steve
Edited by - Steve Stephens on 1 Jul 2004 06:38:27