Dirty radiator water

[rbray]

I have am having the following problem.
When I first got my 351 crate motor I replaced the reverse rotation water pump with a standard rotation water pump. I didn't know that I also needed to replace the timing chain cover. As a result I had a water leak that I tried to stop using Stop Leak.
I replaced the timing cover and all is well except that the radiator water is dirty. I have tried flushing the system several times and the water is still dark. The drain valve on the radiator has a slightly oily feel to it and I'm worried that I am leaking oil into the cooling water. I am hoping that the dark water is due the Stop Leak. What to you guys think?
Roger

[427sharpe]

Bars Leaks will turn water brown, but I don't know about others. to clear ir out of the system, I would reccomend you backflush the whole system until clear water comes out, and be sure to clean the expansion tank. You can buy the plastic 't' to hook into a water line and backflush with a graden hose--just don't go crazy with pressure.