ORIGINAL: hogflyer
Actually, its not a waste of money at all. After I use up the glow heads I'll still have a lot engines left I do decide to get an aftermarket head assembly. If I figure $4.00 each for the glow heads, I'm sure I'll be able to auction the engines off for at least $3.00, if not more especially if they are no longer in production and parts are not available from Cox, if I do go and auction them. Besides, the Sure Start runs just fine on the stock glow head.
I agree with all of the above...but then, you are not buying them just for the plug. You have plans for the rest of the engine.
BTW, I have a dozen or so of the Sure Starts, albeit half of them are in the Star Wars Naboo fighters (sale at Tower - $5.99, I think).
As you said, those engines run great.
George