I live in Sweden and have a converted Colorado Pick Up (2006) with 2,8 lit engine. The Swedish importer converted aprox 200 new cars "new" 2006 and sold here in Sweden. Both for 2,8 lit engine and for 5 cyl 3,5 lit.
The kit was developed by a tuning companyin Sweden (I was earlier the part owner in this company) is still possible to buy by another company who have taken over the selling rights for the kit. The kit include also a fuelsensor that makes the cars "flexifuel".
I will say my car have worked well without problems since many years.
So if you are interested to make your Colorado´s flexifuel look at www.bfv.nu
If you want more info please put an message here or mail me.

Best E85 regards
Rolf