My '86 carburated K-30 with a 454 & Turbo 400 still runs at 230 degrees at 70 MPH even after a new 4 row radiator, 160 degree thermostat and 17" flex fan. During City driving the engine runs pretty warm also. The Carb was recently rebuilt by a competent shop and timing is at 4 degrees advanced (a little low) mostly to compensate for the oxygenated fuel in Los Angeles. I was thinking the stock water pump might be the culprit, but unless it leaks, there isn't much that could go wrong with it. That may be my next step along with bypassing the interal cooler for the trans and just running the external one. I'm curious whether anyone has had this problem and what they have done to solve it. Any suggestions would be appreciated.