Digital BW, The Print

I have an 1160 with cis running enhanced generations. I started having to do too 
many head cleanings so i figured it was time to change carts. Prior to the change I 
made sure I had a clean nozzle check.
I put the new carts in and the nozzle checks never came clean.
I tried all of the variables to rectify the problem. Cleaning carts, new epson carts, 
head scrub with paper towels that have been dampened with with the "Windex 
treatment",drops in the pads,pulling the carts and some drops in the spikes,fitting 
some tubeing over the spikes and injecting "Windex". I let them sit over night or for 
days. It got to the point where no ink was coming out.
Is it possible that the new virgin carts had something in them that contributed to the 
problem or is it just time for new heads.
I have used the cis for 3 years and changed carts in the past and after a couple of 
cleaning I was up and running again.
I am planning on getting a 7600 ,or 9600 and also wondering if I should dump the 
11660 and I figure I had a wonderful relationship with it.
Thank you all in advance for any advice,
Love and Peace,
Raphael sloane