I have always gone with the rule of 2.2 in a light car, 2.5 in a heavy car. The 2.2 love to rev, 2.5 not so much-Not saying 2.5's can't rev, but they prefer under 6k. you want to have a motor that can rev in a light car and one that makes it power sooner in a heavier car.
My brother has a showroom stock original '85 GLH, mint. 2.2 carb. I am telling you the 2.2 is suited to that thing. has fun with integra "ls" models and stock 3.8 liter mustangs
I have a 2.2 TII in my Lancer Shelby. Its a great motor, turbo hauls. I have a very special affinity for the 2.2, but the car feels as though it could use the extra [if you will excuse the expression] "oomph" or torque that a 2.5 can provide in day to day AKA stop and go grind of driving vs having to work the shifter more often that i would had the car come with a 2.5 TII.
Dont get me wrong, the 2.2 makes decent torque, i can leave in 2nd gear and 3rd if i feather the clutch around.. but the 2.5 would have a tad more authority in this area of having to create momentum for this cars 3000lbs curb weight.
My only areas where i wouldn't recommend a 2.5 is that I personally dislike the tuna can sized pistons and how they rattle around. but i understand why they are the way they are. And the balance shaft business as its not something you want to do to a daily in your driveway [though you can,] on a given weekend incase the usual happends like a bolt snaps or what not. If your building one [2.5] on an engine stand, then its really a non-issue
anyway, that's my view on the subject. I hope it helps.
bernard
TurboDodge.com 
