Sticking with questions on the 69 gas tanks. My tank is in very good shape except for the fact that the sending unit is not functioning properly. Even with a full tank it only sends a high resistance ground to the guage so it never show over 1/8th full. That is the only thing wrong with the tank. The gauge tests good. I really don't want to replace the tank since I installed an in-tank electric fuel pump about 3 years ago (great security when used with a cutoff switch). How difficult is it to change out (or have someone else change out) the sending unit? Staying in the "gas" arena, Recommendations for type of gas to use and what lead substitute additive have owners had the best results with? Thanks, Bob - '69 GT350 CV
Bob: Good questions and nice to get back on a parts theme. The sending unit is not a hard change. You will need a new lock ring and neoprene seal as well as a new sending unit. Then it is a case of removing the old unit and replacing with the new. You will want to either take the tank out or drain it completely before making the switch. If you take the tank out, not a big job, you may want to clean it out to remove any grunge that has accumulated over the years. Here in Canada, I use Sunoco 94. I use no lead additives at all and this is for a 428CJ. I believe in many parts of the U.S. the top grade is 93 and have used this on trips to the U.S. with no ill effect. On a GT-350, you should be able to use a grade below that with no problems at all. The lack of lead in gas being the cause of valve seat failure has been overstated in most cases. IF, and only if you race your car or drive it at high rpm's you are at risk of causing valve seat damage. Under normal driving it should be no problem. Hope this helps Ron ----- Original Message ----- From: SealFase@aol.com To: shelbymustang@carmemories.com Sent: Monday, July 11, 2005 10:17 PM Subject: Additional Gas Tank Question Sticking with questions on the 69 gas tanks. My tank is in very good shape except for the fact that the sending unit is not functioning properly. Even with a full tank it only sends a high resistance ground to the guage so it never show over 1/8th full. That is the only thing wrong with the tank. The gauge tests good. I really don't want to replace the tank since I installed an in-tank electric fuel pump about 3 years ago (great security when used with a cutoff switch). How difficult is it to change out (or have someone else change out) the sending unit? Staying in the "gas" arena, Recommendations for type of gas to use and what lead substitute additive have owners had the best results with? Thanks, Bob - '69 GT350 CV