New in the original AC box, #6462849. 028 0 date code (28th day of 1970)This is the old original style for a rallye gauge Housing is an eggshell black, with a gold irridite male end. Pics upon request. Asking $220 plus shipping, will consider offers. These are very hard to come across.
OK, I'm going to help Tim out here and cut through all the confusion. I already did this research for an article I never finished. #6462558 is the 80 PSI sending unit for Early 70 455 cars with gauges #6462849 is the 60 PSI sending unit for Mid 70 thru the end of 72 production 455 cars with gauges I cannot read the sheet out of the assembly manual (Page 6-7.2 Dec. 22, 1969 version) to get the exact date but the changeover was in the middle of December 1969. Through research I have found the gauges stayed the same for 70-72, so there must have been some reason in the engine to force the change. All 71-72 455 engines have the oil passages opened up. I know we had to do this when we rebuilt my early 70 Stage 1, but didn't have to do this on my late 70 Stage 1 (May 70 build.). The thought is that Buick must have opened up the oil passages sometime during the 70 model year. Now its a simple law of fluid dynamics that if the flow stays the same and you make a pipe larger then the pressure goes down. That is why I figure Buick changed the sending unit, so the gauges would read correctly on the "opened-up oil passage" motors. (It sure would be a lot cheaper to change a sending unit then to go thru all the hassle of re-calibrating a bunch of gauges, especially for the ones that were already in stock in dash clusters.) The bottom line is this, the only gauges that will read correctly with the "80 psi" sending units would be early 70 motors that were not drilled out. ALL other 455 motors, in the 70-72 model years, need the "60" psi sending units, or the gauges will not read correctly. Now that that's settled Tim can get back to his sale, and all you other guys will know what you need for your motors. Duane PS. You can thank James Weinman for helping me with this research.
