each to their own.... i would rather go the sprint for:
far superior handling (i'd go as far to say my sprint handles nicer than my mum's EL GT, breaking the sprint is no match lol).
i would say the 302 windsor has MUCH greater potential to the I6 (NA speaking of course).
the sprint has as factory fitment a cobra manifold, 24lb SVO injectors, GT40 heads, crane race series 1.7 RR's and weigh only 1580kg. Have you seen the aftermarket parts available for the 302 Windsor - especially in the US!
mine is relatively bog stock and is side by side a VR GTS 5.7 litre 6speed thats done a 14.1 - All i've done is timing, k&n, pacemakers and 3.45s.
not one NA I6 E-series falcon i have raced has come close in a race.... even on the dyno - a EL XR6 would pull 165 @ the treads, mine makes 225 - and weighs less...
i will say however that the EL's are in my opinion the best designed and manufactured falcon to date - excellent build quality and very reliable.
I personally suggest you ditch the whole tickford idea, and buy a EL half the cost of a sprint or XR6 and drop in a XR6-T donk.
Then you get reliability, a relatively new car and something almost unbeatable down the 1/4. You dont pay through the nose for the tickford wings which is not all that bad because you're simply paying extra for the badge, a cam, a very mild tune improvement and a slightly improved suspenion.
Not to mention insurance companies will eat you alive (my sprint is $2600 a year to insure, hence why its time for her to go).
hope my ramblings shed some light on your dilemma