[wga]

Is this a stock motor? Let's assume it is. Check to see if you have exhaust gas in the coolant. Go to some independent shop in your area and ask if they would use the exhaust gas probe to check for exhaust gas. If you get readings of CO2 in 15 - 20 PPM or so range, you could have a bad head gasket, at worst a crack in the block. A good reading is 4-5 PPM If this test passes - then look for the usual problems - but let us know if it is stock, modified, etc. Could be as simple as the timing is set incorrect. Get some thermostats installed, 160's and get back to us.