I have an opportunity to purchase a set of alum. bbc rect port heads with 2.25"int. and 1.88" exh. I have looked everywhere for more info and spec's on these and cannot find anything. Have mercury cast into them and casting#'s are 900-843425. If anyone has any info or ideas I would greatly appreciate it. I don't want to pass up this deal, I'm getting them from a friend super cheap! Thanks for any help.

They are only super cheap if you know what they are. Otherwise they are expensive paperwieghts. Doesn't your friend know what they are from?????? I'm not sure what factory mercury engines had aluminum heads, but there aren't many other than the 525EFI's that I know of. BTW, 525EFI heads are an edlebrock casting that will only bolt up to 525EFI headers.

I have heard that if you enlarge the bolt holes on the regular headers you can make them fit, I have not tried it myself only hearsay.

He took them in trade for some work a while back. I also forgot to mention, he said they came off a 572ci. As far as super cheap goes, $ 500.00 completely assembled even if I don't have all the spec's seems awfully cheap to me. They are definately worth it, hardly any time on them .Thanks