replacing a bad omc 302 block

I have a 77 20' fiberform with water in the oil. I got the boat this way 2 or so years ago and am getting ready to go thru it so i can use it next year. This is my first boat since I was young and I don't have any experience working on boats. I do work on my vehicles and some others so I'm not completely in the dark though. From what i've learned so far I most likely will have to replace the block and get my internals refreshed and swap them into the new block. While I have it apart I want to go thru the outdrive also and get it to where I can trust taking it out to catalina and fish without the worry of breaking down at sea. I don't know where to try to obtain a block that I can use or find the manual(s) for the motor or outdrive. It's a 175 OMC with the matching outdrive, both OMC. where can I find this info is my question. Thank you.

Re: replacing a bad omc 302 block

Welcome to the insanity of boat ownership..

Heres a link for the OMC manuals

http://forums.iboats.com/showthread.php?t=309093


I would imagine a used 302 block properly marinized is ok, especially if you swap all the innards over..Make sure you keep the marine carb and all electrical componets marine rated..Starter, Alternater..ectera
..Others smarter than I will chime in..

I have to say...Going to Catalina in a 20ftr..well ya had best pick your days, go across early and get back by 3:30 or so..You know how the wind comes up through the channel..

I fished the backside of that rock for years in my buddy's 25 ftr..and had some pretty rough days..

p.s.
I would just see about swapping that OMC out to a mercruiser if I was going to have it out of the boat anyway...

Good Luck

Re: replacing a bad omc 302 block

thank you for the info.

Re: replacing a bad omc 302 block

Wow, it's way further from Long Beach to Oxnard then it is to Catalina.

Re: replacing a bad omc 302 block

Yeah, and there's no cute song about going to Oxnard either! I would not want to try to get into that harbor at night.

Re: replacing a bad omc 302 block

Other than a change to one piece rear main seal and dipstick location, all 68-02 302 blocks (and I am talking bare block only) interchange. 'nutcase

Re: replacing a bad omc 302 block

What is wrong with the block you have? If it is not cracked, tear it down and have a machine shop bore it, replace the low compression dished pistons with flat top pistons, swap out your marine cam, replace the timing chain set and you'll be good to go. I'd also have your valves inspected and at least lapped while you are at it.

Any used block that you get, you would have to do the same thing with.

Oh, and also stay away from any ?85 and newer 5.0 liter blocks. They are roller cam blocks and you won't be able to use your marine cam.