I've got a set of heads here, PN on the front head is 17090-06. I know that this is a Mercury Marine casting, but how can I tell what years or models used these? Planned on using them on my 95" FLHT.

 

I believe that's a casting #, not a part #. You'll be fine using those on your 95" motor.

 

Sorry, typo. Yes, that's the casting number. Not sure how long they used that casting.

 

Since 06. Does it have bee hive springs?

 

I have a set of those heads and mine came off a 2007 RG.

 

Yes, 06 casting used on 07 up bikes w bee hives.

 

Indeed, beehive springs. But how can I tell if they are compatible with my pistons, motor mount, etc?

 

Unless you have HTCC pistons they will fit, flow better and support higher lift springs.

I forget which year they went with the extra motor mount on touring bikes, but they will fit also. But now that I think of it, since the newer ones are drilled for ACR's, you will have to visually check to see exactly what you have, newer touring, newer 103's with ACR's. They still all fit.

Jim