The OEM proportioning valve lowers pressure to the front calipers, in an effort to improve brake bias front to rear. Once removed, you'll have full pressure to the front calipers but your braking bias will be even more to the front than before. Putting an adjustable proportioning valve in the rear circuit isn't necessary with stock rear calipers as there's zero chance you'll want to reduce brake pressure to the rear calipers.
PANTERA INTERNATIONAL
A DE TOMASO CAR CLUB
Presents the De Tomaso Forums
The On-Line Meeting Place for De Tomaso Owners and Enthusiasts From Around the World
Clicking on the banner will take you to the sponsor's website.