Brake Bias
 

I have read before that the 94-97 cars have better front to rear brake bias to a changed proportioning valve. Is this true? If so, would it be worth it for me to swap in the proportioning valve on my 96M into my 91? The 96M also has ABS, does this change anything with the proportioning valve?

Thakns, that graph is from the FM website right. I knew I had seen something like that before but couldn't remember where.

I never thought there would be that big of a difference with ABS vs non-ABS. I guess if you lock up the ABS it doesn't matter if it locks the rears first since the ABS pump will take care of it.

If you're going to swap the proportioning valve, just go with an adjustable. A different valve from a different year is just a different valve from a different year. Since ideal brake bias changes per the discussion in the linked thread, the adjustable valve is your best bet.