They heavy cars due to heavy front and rear subframes, 1400kg if i remember right.

2litres are about 170bhp

2.6s are only 153bhp because of a very restrictive CAT and zorst, and a small turbo.
Jus waning on a bigger turbo and sorting fueling to match is meant to give 250bhp or summat on 2.6s...
ONLY external difference to know its a 2.6 is that it has no headlamp washer jets in the grille...

Ah fuck all this, jus found this...

http://homepage.ntlworld.com/mark.stacey1/tuning.html