Just bought a 63 ranchero with a 289 in it. the 260 is long gone. Looks like a pretty stock engine. It was leaking oil, so I took the maniolds off and the heads. It looked like it had the origonal valve seals and a few valves did not. Bought new ones to put in. Can anyone tell me if the origional seals were made of rubber? The ones in the heads are some kind of plastic. Also, when I removed the valve springs they were really short!!! Bought new replacements and they are the right height free standing per specs. Compared to the ones I took off, the old ones were almost 1 inch short--all of them. Is there some benefit to putting in short springs?