OMC 4.3 liter gear ratio question

[JustMrWill]

As some of you know...last year I injured my lower unit on my '87 OMC 4.3 liter V6 stern drive.<br /><br />I found a really great deal on a rebuilt one but my luck has held and it was DESTROYED in transit by FedEx. The person I purchased from got another one in that he is rebuilding BUT he seems to have gone on vacation and I can't reach him. (last communication was in January and he had to order some parts) I have all but given up on him and started a search for another one.<br /><br />Now onto my questions:<br />Am I correct in my belief that the lower is the same on 2.5, 3.0 and 4.3 liter models?<br /><br />Is the only difference the upper gear ratio?<br /><br />Do any of the above stated models have the same upper gear ratio?<br /><br />I am just trying to figure out what I can look for on EBay (full stern drive versus just the lower...etc).<br /><br />Thanks in advance.<br /><br />-JustMrWill

 

[Laddies]

Re: OMC 4.3 liter gear ratio question

21/19 ratio

 

[JustMrWill]

Re: OMC 4.3 liter gear ratio question

Thanks...<br /><br />anybody know wat one off a 3.0 liter or a v8 is? Trying to determine what is for sale on ebay will work on my boat. <br /><br />-JMW

 

[Laddies]

Re: OMC 4.3 liter gear ratio question

5.7 and 5.8=21/16---5.0=21/18 sorry I can't seem to find the 3.0

 

[JustMrWill]

Re: OMC 4.3 liter gear ratio question

Ok...so are the lower units interchangable? If I was to pick up a complete sterndrive is it "as simple" as swapping the upper gears to get the ratio correct?

 

[JustMrWill]

Re: OMC 4.3 liter gear ratio question

^