38/62 refers to the weight distribution not braking bias afaik. There are only 50/50 BMC's for Delorean application unless a proportioning valve is utilized. DMCL decided one wasn't needed due primarly to weight transter which puts 70% of the braking force loaded onto the front wheels by default in most applications. The only significant difference between the Saab unit and the DMC is bore size which is a tad larger which if anything gives a bit more stopping power. Without a P.V. however both units are 50/50. I know this because I switched to rebuilding using brass sleeves due to the poor quality of most recent offerings. Urban legends die hard.
Rob