Re: chevy HO manifold water flow
Looks like a Performer RPM series manifold...
Not a good choice for off-roading. Off-roading requires lots of idle and low rpm operation, both of which Performer rob to pay for upper end rpm performance.
If you are doing mud bogging or something like that, it should be fine for your application.
As for heater hose line placement...
Heater feed should be on the water pump it's self. Look for it on the passenger side of the water pump.
Return should be the hole staring you in the face in the right front corner.
This one keeps the hoses as low in relationship to the block as possible.
You can always return to the radiator, if your radiator has a heater hose nipple.
Some heater hoses return to the top side of the thermostat housing.
Run either one of your heater hoses higher than the top radiator hose, and your heater will NOT work.
Here is another little tip for people working with raw cast aluminum...
Use Plumbers Dope and not tape when you insert the heater hose nipple.
DON'T OVER TIGHTEN! Let the Plumbers Dope do the work, 15 to 25 INCH POUNDS (NOT Foot Pounds!) is all you need to keep the nipple in place.
If you over tighten, you WILL crack the intake right through the water passage.
Use new bolts & washers of good quality under your intake bolts also. This will keep your bolts from cracking and distorting the intake flanges.
If at all possible, Before Installation, Heli-Coil the threaded bolt holes, like the carb mounting holes you are going to use, and the water neck holes.
Threads pull out of raw cast aluminum so easily, and raw aluminum seizes to steel bolt threads so very easily...