210 is good from what I understand with thee engines. Lowest to highest should be withing 80% if I remember correctly so your 205 is withing specs.What are suppose to be the compression numbers for a 2005 colorado 3.5? i had mine done and they got 210 on 1 through 4 cyl and 205 on 5 cyl. I have 63,000 miles on her. Thanks.