I have used Dave Andrews guide a few times with great sucess...last kit car I tuned on carbs was modifed using his guide and made lovely power right though the rev range....

http://www.s262612653.websitehome.co...s/dellorto.htm

Twin 48's on a 2 ltr pinto I assume? does sound a little large so you might find it a little lacking in effciency...

HTH

Ian