So you want people to pony up $12k for a pair of heads that they know nothing about? Just want to be clear here.
No he wants a bunch of small donations that could hopefully add up to enough money for a prototype set of heads. Usually in crowdfunding cases like this people get perks for being backers. Having a chance to buy the first set, cheaper then retail, etc etc.
So I'm misunderstanding this part?
To answer the question of producing the head. Minus valvetrain, 12k gets you a set of bare cylinder head(ie cnc machining, valve guides, seats, etc).
If several people collectively donate $12k, who is "you" in this....who gets the cylinder head(s)?
Things like this need to be stated clearly...what each person gets in return for the donation, what gets accomplished for the X amount, what still needs to be done before actual working cylinder heads can be shipped out. Sorry if I see red flags...been through this song and dance before.