Hey guys, I'm looking for some information. I'm building a 99 5.7 Vortec to put into my 86 Camaro. I'm at the point of the build process where i need to put the accessories on. Id like to put the v belt system back in because it is much easier than the vortec serpentine system. The problem that I'm running into is that i have no idea if my 99 block is reverse cooled or not. I have a new Water Pump that i bought for my recently deceased 305. However it has an extra coolant passage that the vortec block does not accept. I'd like to weld the passage shut and use it seeing how i already have it, but then theres the whole reverse cooling thing. Also we are taking the AC out of the car because i have T-Tops. My next question is, where can i find a bypass pulley that will also act as the tensioner? I've seen people use a 2nd alternator in place, but i don't think i want to go that route. Thanks in advance for your guy's help.

 

"Reverse cooling" is heads-then-block used by the LT1/LT4 engines only. The water pump is driven off the cam gear through the timing cover. Not interchangeable with your 305.

The question you have is standard (V belt) or reverse rotation (serpentine). A V belt water pump turns the same direction as the crank. A serpentine belts wraps the back side around the water pump pulley, therefore rotates the pump reverse of the crank. While the different pumps will bolt up, water flow and cooling with not be correct.

That extra passage on the water pump is the internal bypass... to keep water circulating even when the thermostat is closed. This is an old, non-Vortec style pump. I don't think welding a cast iron pump will give you a good, long term seal. If the block has a mating surface, you may be able to simply bolt it up, and it will seal against the block.

The heater core can serve as your external bypass. The factory diverter valve will bypass the heater core, and still flow coolant to the radiator. If you change the factory heater lines, make sure water will always flow to provide your bypass need.

If you are switching back to V belts, simply leave that belt off the car. If you are staying with the serpentine setup, search for AC delete pulley.

 

I did some research and my block doesnt fit the peramiters of the lt1/lt4. However the pump i pulled off is ran by the backside of the serpantine belt wich indicates reverse flow. Hence the confusion. Also, if i go with the V belt i still have to run the PS pump. If i remember correctly the AC pump acts as the tensioner, which i want to remove.

 

I looked up the casting number today and it says its a gen 1 crate motor.

 

... reverse cooling isn't determined by the direction your water pump rotates...
A serpentine system just uses a different waterpump because it is rotated the opposite way as a V-belt.
"Reverse Cooling" is an Lt1 concept in which the coolent flowed through the heads first.