those are my heads. they have 5000 miles on them using prestone antifreeze that is rated for aluminum. this is not 100% 440sources fault. its mine for running both grounds on the heads and not the block BUT when i emailed brandon he ignored me, i emailed again telling him i had sorted out the problem without his help and he ignored me again. the third time was to tell him he was a dick and thanks for blowing me off, his reply was if it was a problem i should have phoned and since i sorted out the issue he didnt care what the outcome was. if you follow the source threads you will find this is common with brandon

i was like you guys defending 440source in every fight (just ask JohnRR) but the way i was treated i will never spend another cent with them.
so so far i have had to put locks and retainers and repair and surface both heads. so the initial outlay of cash was ok but with repairs and replacing junk parts i am over the price of a eddy head

you guys that are running these heads, have you had them off since you put them on? you may be in for a surprise!!

bottom line is its your money buy whatever you like. just telling my experience with the quality and company.