Is it safe/adviseable to run homemade salt away through the big block engines/drives?
I see where some run a mixture of vinegar/water (without the soap).
Recipe: small amount of vinegar, small amount of car wash soap or Dawn...lots of water

Why not just use salt away? I know people use different variations usually in a pinch. I buy the 5 gallon jug on eBay and keep refilling my small bottle

If you read on the site, you'll find a good many mixed results from the use of salt away. I squeeze some Dawn into the water manifold after letting water run through the engine(s) and then continue flushing. I have not had any issues and I'm in salt all the time.