I had a Chevette heater core with shroud collecting dust and a Aquaxtreme 50Z pump. I got several Aquaxtreme/Cooltechnica blocks. I went with the MP-05 SP. Note this is NOT the newest version as the pin count is less. However the performance is still very good.
I decided to put the rad on top of my case in the back. I never liked the rad inside the case. I like the idea of outside non restricted air flow. Also in this configuration I can use the radiator as the rez/air bleed. All I had to do was drill a hole and solder on a barb pointing up and clamp on some tubing. This worked as good as I thought it would.. Took a couple hours to bleed but after that no more bubbles in the lines. I put a Panaflo 75 CFM fan on the shroud and lowed the voltage to around 6V to shut it up. With the fan at full speed the temps seem not to budge to much.
System Specs.
AMD 64 3000+ Stock speed 2ghz currently running 2,660mhz at 266fsb. Stock voltage.
2gig cheap DDR400 not overclocked.
200gig IDE ATA133 7200 8meg cache Maxtor. Failthful for a few years now.
Radeon X1950Pro 256bit 256meg GDDR3 Stock. Not much of an overclocker.
ASRock K8NF6G-VSTA mother board. Has been rock solid.
AquaXtreme 50Z 12V pump
AquaXtreme MP-05 SP
Temps are excellent. However the 50Z pump is LOUD as hell. I hear they take a while to break in and quiet down but if it doesn't quite down back to air and the XP90.