I did a TPI swap a while back. I Cant figure out which plugs I should use, the original plugs for the "G" block (.045 gap), or the plugs for the TPI block (.035 gap). I have the stock "G" block, with a TPI top end. The plugs for the "G" block seem to run a little smoother, but the engine surges sometimes at idle. The plugs for the TPI block runs a little worse, but always Idles perfect. ?????????