the larger return would lower the pipe's friction/resistance and thus allow the returning coolant to be at a slightly HIGHER pressure.
higher pressure at pump suction reduces the possibility of impeller induced cavitation.
if the system's pressure setting of the radiator cap was on the suction, it would make little differance
the curtain area at full open (1/4") is the area of the original coolant tubes
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.