[skyjgmc]

well you learn something new everyday!! about 6 months ago I bought some spark plugs for a 1970 gmc with a 307, the other day I finally got around to trying to install them well turns out they didnt fit, the old plug that came out was a AC delco R44TS so I had Oreillys look them up to see what SBC they would fit and it looks as if my motor is a 73 or newer 350 not the 307 I originally thought even the previous owner was confident it was the 307 and the stock motor. Im kind of excited to see that its not a 307 but now have to climb in there to get the numbers off the block to see what exaclty it is I have swapped in there. I aslo rejetted the carb and fine tuned the timnig and it runs so much better now and with the proper gapped plugs it should be good to go for the summer and camper towing duty.