GTSIO 520/550 vs reg 520 cylinders for GPU Conversion (COST?)

[luv2airboatnhunt]

Hey folks, I know this is a "running dry" topic, because I've read everything I could find in SA Forum back to 2010 that relates to GTSIO 520 conversion. These forums are loaded with experience (and BS, as expected...lol), so I found most of the answers I was looking for, but this one....
Looks like the GTSIO cyl, parts, and rocker assy are getting costly. What is the going (avg) price for 6 cylinders, rocker assy, vavle covers, ready for pistons? Has anyone bought any lately?
Now, what about GTSIO 550's? Newer style cyl, are they worth the $? Anyone running a set?

All responses are appreciated,
Thanks...

 

[mrfixit]

As you should know gtsio rockers are really hard to come by. You will probably not be able to find this all together and have to gather together one peace at a time. i use gtsio cyls on a few of my engines and i had to make most of the parts myself. There was someone making after market parts a wile back ,but I do not know how good they were.
Good luck .