Cooling System Flush Advice Needed

[dhunt00c]

Hey gang...

Could use some advice. I had a mildly used 350 crate motor that i put a cam and aluminum heads on. Sat for years but i cleaned it up best I could in process.

I setup on engine stand and used brand new nice radiator for my truck to break cam in. All is good but after running it, but now I noticed the radiator hoses have a crust on the inside of them i'm guessing from the messy internals of the engine cooling system. I could tell when i gave them a squeeze. It was like a crunchy film had attached inside the hose. Haven't inspected further.

What's the best way to flush some of this out while it's on the stand so that don't ruin or plug up my new radiator or get a thermostat sticking? I want the engine tuned and good before i install in painted truck. Are there any honestly good chemical treatments to get all the passages, hoses, radiator as clean at least as possible without disassembly and hot tanking the thing?

Thanks in advance