Chevy Mercruser Head ID help

[OMC-ALLtheWAY]

I cant find any info on a set of heads I have. If anyone knows any info please post it. It would be a huge help. The casting # under the valve cover is3886336, the 6s could posibly be 8s or 5s. There is a stamping in the end of the head that is 65392. They are 1982 mercruser heads I dont know the rating of the motor any help would be great thanks

 

[OMC-ALLtheWAY]

Re: Chevy Mercruser Head ID help

I am looking for combustion chamber size ccs and valve size thanks

 

[qystan]

Re: Chevy Mercruser Head ID help

Look at the left rear 10 o'clock position on the main engine block (not head) just behind the cylinder block. The number is cast not engraved. You might see something like GM57SGI = 5.7 L<br /><br />Look on the forward right side just below the dipstick tube. There is a flat machined surface, you can see a stamped number, last 2 letters gives you the engine config code, number just before that is the year of manufacture 9 = 1989 or 1999 etc.<br /><br />Valve sizes are given in the service manual.