270 for a .21 promo kit....Thats seems like a sweet deal... during break in on mine, half way through idling my tanks through on the work bench it wouldnt start up anymore. The grp plug was blown. I put in a new plug and it fired right right up. I thought it was something I did. Its funny how everyone has different preferences on plugs. A guy at my local track that has ran several Grp's swears by the Grp plug.