Engine flushing Question

[rposton1]

I have a Gen6 crate motor from indmar and it had the stock water jacketed headers. I was wondering what the best way was to flush the motor, I have removed the two 1/4 in plugs in the lower part of the block and alot of sand came out. I want to flush it out but am worried about getting water in my engine from my headers do I have any thing to worry about? Thanks In advance Rob

[SmokinLowriderSS]

If you have JACKETED headers, you should have no trouble. The water dumps into the headers after they arch over for drainage (are they OT or TT, I have TT's). Jack the bow up as high as possibe if you want more peace of mind.
I would disconnect the supply hose, put on a garden hose adapter,and turn the water on Gently. Don't overpressurize it inbd of the controll valve. I would poke arround thru the plug-hole with a wire while flushing. Good luck.
I never did flush, nor did dad, 27 years, and while there was some sand in my block last year, it wasn't a lot. I don't boat a lot arround sand tho, Ks lakes tend to be mud-bottom covered in rocks, Okla lakes tend to be rock bottoms.

[rposton1]

Thanks so much for your help :) Rob