Have a pair of Merlin heads I want to sell but do not know anything about what they are.They are square port,has 3 different casting # s under the valve cover.1 is (1-043) 2 is ( F24 ) 3 is (dot 91 dot ) there is also a W by itself and a NH by itself.Anyone with knowlege on these. Thanks so much JOHN SR

this is what I found

310cc, 2.19/1.88, 119cc rectangle port
F24 June 24 *91* year 91
1-043 is port type

Think these heads are good HP boat heads Thanks for your help JOHN SR

They are definately a very beefy casting. IMHO out of the box they are not much better than a GM head. If you can find someone to grind on them it's a different story. Last set I had I ended up giving them to a friend of mine and they have been sitting on his mock up motor for a few years now...

being really honest,,No.