having had both and still owning 440 source ones i can answer that.

my source heads were the first generation. they needed locks and retainers out of the box as they were poor quality. emailed brandon and never even got a response (you will soon see a pattern here). no biggie.
bolted them on my 383 while i was building my new 383.

pulled them and took them to dodgefarmer (randy) to check out how they were holding up after 5000miles before i bolted them to my new 383. apparently they had huge amounts of porosity around the water jacket areas. Randy fixed them up (again) and was back in business.
emailed brandon again. ignored. send him another, ignored. sent him a final one saying thanks for nothing and the problem was fixed. nothing. He then emails and says he doesnt consider it a problem unless i phone and since the problem was fixed he didnt feel he needed to talk to me. my final email was to brandon sugesting some places he could "store" his parts on his person.

if i was selling a product that was poor quality i would want to know what caused the problem. he obvously knew about the problem or didnt care as they were selling well anyways. ride the train until it falls off the tracks i guess

i have probably around $1600 into these heads right now. I bought them for the sole reason to save a couple dollars. in the long run i could have bought eddies and never had any problems.

i have posted of this issue here before and electrolisis may have been a issue. IF thats the case why didnt my eddy heads do the same thing? cheap castings on the source stuff

thanks brandon i hope my post brings in some business for you