Dear Mr. Porter,
Zero.
There were no takers at $3,500. So to reinforce the the fact that we no longer had any desire to port iron heads, the price went up should anyone inquire about some.
When I had more money I offered to hand carry the heads to anyone and install them on their engine so they could see the difference. Again, no takers. Well hell, we all know it's impossible, why waste the time.
And now no desire to repeat the offer. Building engines was only really fun when we were doing them for ourselves.
