I just set in another 454. I'm wondering if I really need the coolant by-pass hose? What's the pro's and con's on this. Another question is if my intake has no outlet for the vacumn hook-up for the trans (400 turbo) can I get this off the double pumper somewhere? There is no vacumn port on this manifold. Thanks for all your help, Rick

Rick,
You should have the hose in place to alow the water to circulate until the thermostat opens. The water will leave the intake and be sent back through the engine warming it up to the point that it can heat the thermostat enough to open. I think if you block the hose you will end up with hot spots in the head around the exhaust ports while the temp of the water in the intake near the thermostat will be to low to open it.
Use any of the vacuum ports in the base plate of your Holley to control the trans. My double pumper has a port on the passenger side near the front of the carb that uses the right size hose for the line to the modulator on the trans. I ran mine with this port before changing manifolds. The only reason I moved the line to a fitting on the manifold was to have one less hose to mess with when removing the carb.
GaryR