[homemade87]

You really dont need a 4 corner system . Gm stopped putting them on somewhere around 04 . I think it was developed mostly for the corvette or performance cars that the engine sit level front to back . If an engine was to sit level ( corvette drive line ) it could hold some air in the rear corner and the vent line allowed it to escape . If the engine was at a 3 degree angle ( most all swaps )down any air would migrate to the front to the vent lines . These lines are not for cooling . They will not move enough coolant to do any good . They will remove any air so you have as much coolant contact to the head as possible to eliminate and air pocket and hot spot .

If you are setting your engine up to be level front to rear I would suggest a 4 corner system . If not the fronts will work just fine . I would not spent the money on a 4 corner system .

All this being said , The op can find the oem 4 corner system on ebay . Expect to pay 50 to 60 bucks . Junk yards would be a crap shoot . They have not put these on vehicles for more that 10 years . There is a lot of aftermarket stuff out there to set one up .