Haha, here people go again with this poly top mess! And did I hear or see someone asking about cracking and barbs... you guys and this eye-geekdom-candy... when will you ever learn that FUNCTION always takes precedent over a potential-flawed form? Can't wait to hear the next post about "my top cracked and leaked, everything is gone, WTF?"
Okay, sorry bout that, had to get it off my chest... anyhow, just by looking at that block design, it says to me "FLOW RESTRICTION" all over it! lol... All those slight curved 90° bends, and add the SMALL separated channels... that block isn't going to perform that well, for the money and time it took to make... Hey I've got a perfect idea! Blocks like that with the clear tops, after they crack on ya, you could use them for like say Flea mazes and train fleas to wander through till the end? Or fill them with a small bead and try and work it through, like a little pocket key chain?
Good luck
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XP 1600+ AGOIA-Y (GreenLabel, UNLOCKED!@/ NF7-S 2.0/ PC 2700 DDR
10.5*172FSB(1806/ 1991 high), Vcore 1.792...@84.95Watts
--86' Chevette Heater Core
--1/2" Vinyl tubes
--Via1300-Stealth Mod(QUIET!)

---Home made copper-tube block
---PVC small internal res