trim system interchange

[redbandit98]

hello all..Im trying to put my 85 mercury 150 blackmax on a newer hydrasport boat. My trim system leaked down pretty quick. I tried to tighten the relief valve and checked the oil...no dice. Im pretty sure the main trim ram is leaking. Ive seen rebuild kits for about 80 bucks, and they want 40 for the relief valve. I have no idea of the condition of the internals of the system. Being its 25+ years old, the cylinder walls could be scored etc. Im just going to try and find a good used one on an online auction site. I would like to buy the newest one I can afford. It seems that the newer ones are all two wires and mine is a three. I know there is an update to convert it and that is no biggie. My question lies with the mounting of the actual unit. Did they all keep the same bolt pattern over the years? Mine has the "snorkel" on the resevoir and the newer ones look like they do not have this. I know that has nothing to do with the actual mounting of the unit but I want to make sure the newer style will still bolt up to my bracket. Thanks for any help.