I had only one Vortec small block, that was a '98 4.3 in a half ton, all stock, so I'm not qualified on them. Prior to that were all '70's and '80's 350's and 454's. I tend to keep things as stock as possible and have not had overheating issues so the bypass mod was not in my sights. With my '57 283, I added an overflow bottle so I can keep the cooling system free of air, it does what I want.

1957 Chevrolet 5700 LCF 283 SM420 2 speed rear, 1955 IH 300U T/A, 1978 Corvette 350 auto, 1978 Yamaha DT175, 1999 Harley Davidson Softail Fat Boy