So after determining with your help that I can use a regular old 66-67 B-body fuel lever sender in my wagon, I want to drop the tank and get a new sender in there. I'm going to need to clean it out though - I have some fine rusty sediment that comes and goes floating around and slowly piling up in my fuel filter (or in last week's case, in my fuel bowls - don't use Autozone Duralast fuel filters!!)

The thing isn't sending very threatening amounts of rust up the line, but I want to neutralize whatever is in there. I think whatever is in there is mostly settled at the bottom of the tank since it seems to appear right after I fill up or after a lot of city driving (lots of jostling about in the tank). It's never clogged a filter on me, but it has gotten a good tablespoon of sparkly rusty silt in there in there over the course of a few tanks.

What combo would be best for a mildly dirty/sedimenty tank? Hose blast + Simple Green/acetone + phosphoric acid? I'm wary of some coatings - POR-15's sounds good, others sound like they need to have perfectly clean and etched metals or else they flake off and cause more problems than the original rust did.

I know the usual answer for initial cleaning is "have it boiled out at a radiator shop" but I've been unable to find any actual radiator shops in my area, just places that have "radiator" in their name but don't do anything other than installs and Jiffy Lube flush-and-fill junk. Though if anybody knows of a good place around Snohomish county, let me know...