Actually, all of the clad coins were being minted in San Francisco and the silver coins were struck at Philadelphia and Denver.
Interesting. So even though the clad dimes and quarters were stuck in San Francisco they bore no Mint Mark? Is that the first and only time that business strike coinage was struck at a branch mint without a mint mark? That would help to prevent confusion in terms of wrong metal errors.
Yeah, I believe '67 was the year they discontinued the Tri-power and used a 4-barrel with 350HP. Am I right? I had a friend who had the '66 Goat, and he fell in love with the '68 "Judge". He took the tri-power off his '66 and traded it in with a 4-barrel. He put the tri-power on the Judge and promptly blew it up. The 400cid engine was nothing more than a bored-out 389. Chris
The 1967 400 4 barrel made 335hp. The option was a 360hp. I had the 335hp with a factory Hurst 4-speed. I had a reworked distributor for more spark advance and cheater slicks.
Actually the ice starts to melt instantly with any metal, but it does melt faster with silver. Unfortunately since there have never been any standards set as to the size of the coins, the amount of ice, the ambient room temperature, or exactly how long it takes to melt a give amount of ice, the ice test is pretty much worthless. In most cases it boils down to "I put ice on it and it melted so it must be silver" Are you sure you don't have that backward. From looking at the mintage figures from each mint I would say San Francisco was striking the silver. During those early years they were really cranking out the clad in order to replace all the silver that was disappearing into hoards. The P and D coinages are huge, the S is relatively modest. If the clads were struck in San Francisco only it would never have been enough to allow for the ending of silver production in 1966.
Interesting feedback on all of your experiences using the SG test. I'm sure there must be a thread where people have posted pics of their testing set up.
Those were sexy beasts. The '65 Chevelle SS-396, the '67 GTO and the '69 Firebird 400 GT are some of my favourite cars. A bit before my time but sure love those cars.
Well Kentucky here is how he does it .. and I quote " I do, REGULARLY, SG tests in just a few seconds. I open and turn on my scale, I get out the vessel I use, (the bottom 2 1/2 inches of a plastic half gallon milk carton,) pour water from an unopened bottle of drinking water that I carry with my scale and the vessel in a Molle bag, put it on the scale, dip the opened paper clip that I use as a coin holder to the depth it will be when testing, then set the tare. This takes seconds. Then I take the coin or bar, immerse it, hold it still long enough to see my 2.97g per troy ounce on the scale. I weight the coin first, then run the test. I DO THIS ON THE COUNTER TOP OF THE LCS. The coin gets wet. Big deal. If it comes to the point that I'm testing for purity, and it passes, I'm buying. I've never had anyone object. Honestly, it's no more complicated than that. The only proviso is that your scale must read accurately to 0.01 grams for the test to be meaningful. This test is DEFINITIVE. The SG is a property of the element, and is extremely difficult to fake. I smart metallurgist can get close, but if you as a technician running the test know what you are doing and why, you won't be fooled. I suppose most people didn't have or pay attention in high school chemistry, but that's all the level of education one needs to do this test with authority.
Thanks, but this appeared nowhere in this thread. Perhaps you were responding to somethng else. I looked back through the thread to make sure I was not dealing with incipient Altz... whatever. BTW, SG or specific gravity is interesting, but I still don't see how he does it as quoted.