Dlampe Dean start with those carbs. Are the sparkplugs gas fouled or
oil fouled? they look about the same. Any gas smell from them when removed? Swap to good plugs with #1 and #4 if new plugs foul, it's not the ign system. With the methonal in the gas and it is eating rubber hoses, I am thinking possible problem in the main curcuit of the carbs and they are leaking down into the cylinders. You don't want to keep doing this of washing down the cylinders. Can you swap carbs with know good ones?? Do you have a GOOD spark tester? this is one that makes the spark jump about 1". You are also looking for a good bright spark. You can unhook the wire from the spark plug and use a test light to ground to see if the spark is bright and jumps also. With the car sitting for a while, I am thinking gas problem. If not, you are looking mechanical. Possible valves not sealing in the heads if the motor sat for months without lossening the rockers. Is there any backfire in the intake or tail pipe?? A picture of the plugs will help. Rick L.