Sterndrive swap-out: stringer for Merc

[recess]

I am working on a 1977 Grady with a 302 ford hooked up to an OMC stringer. Other than the obvious retrofits with the transom, what kind of problems can I expect changing the stern drive to a mercruiser? Which merc units should I be on the look-out for that will mate up to the ford?<br />Or should I swap out the ford for a Chevy 307/350?

 

[JasonB]

Re: Sterndrive swap-out: stringer for Merc

While I understand from past threads that this changeout is ugly, 1973-77 mercruiser used the Ford 302 and called it an 888. It was essentially a #1 or #1R drive mated to the 302. I think connecting the outdrive to the engive would be the easy part if you can get it placed ok. I hear the hole left by the stringer drive is much larger than the Mercruiser. I bet you would also need new manifolds and such, but that is a guess on my part. If the OMC uses the same flywheel, I would think the engine would only need the right coupler to make the connection. The other stuff will likely be tough. There are others around that have been involved in this swap and will be along shortly. I have no experience with the stringer, but have the 888.

 

[recess]

Re: Sterndrive swap-out: stringer for Merc

What is your experince with the 888? From reading these replies for the last week, it appears this OMC stringer would be best suited for retirement. This is my thinking about going with the merc. They appear, from what I am reading, to be reliable, repairable, and durable. My preference would be to also change out the 302 for a Chevy 350 as I have a few years experince working the bow ties.

 

[recess]

Re: Sterndrive swap-out: stringer for Merc

What is your experince with the 888? From reading these replies for the last week, it appears this OMC stringer would be best suited for retirement. This is my thinking about going with the merc. They appear, from what I am reading, to be reliable, repairable, and durable. My preference would be to also change out the 302 for a Chevy 350 as I have a few years experince working the bow ties.

 

[Bondo]

Re: Sterndrive swap-out: stringer for Merc

The Best way to do what you want to do is;<br />Buy a Donor Boat, with the driveline you want... Strip it,+ use All the parts you need... That way, You'll Have All the little Expensive parts...<br />Go with a Chevy-based engine.. Merc. only used the Ford motors for a couple years... There's Parts for the Chevy-based units Everywhere... If you've wrenched on the Bow-ties enough, You'll know enough to stay away from the 307,+ go with the 350s....Not the 305s...

 

[recess]

Re: Sterndrive swap-out: stringer for Merc

Thanks bondo, that's what I am planning. The current set-up is useable and working, but I intend to keep the boat for a while and would prefer a more "user friendly" drive train. <br />Any suggestions on which Merc units to keep my eyes open for? I, MR, Alpha? I'm in no hurry as the current setup is useable but would like to know what I should be looking for to hook up to a remanfg. 350. What year's to stay away from, etc.

 

[JasonB]

Re: Sterndrive swap-out: stringer for Merc

I'm happy with my #1R drive. My 302 is making somewhere in the vicinity of 225hp and the drive seems ok. I think the #1R and up are rated for roughly 275 with the proper gearing (1.5 in this case). All the mercs #1's are the same btween the different engines I think. The differences being gear ratio and engine coupler.<br /><br />Bondo is right on that Chevy parts are plentiful, but Ford parts aren't hard to find either. I like my 302 since I am a Ford fan and it is quite unique to have a Mercruiser/Ford powerplant and is easily worked on. The 302 is a solid motor if built right. Heck, most of the bolt-ons on my Ford are Delco. The carb, alternator, fuel system, etc are Delco. The only parts you couldn't get from your local auto parts (basic engine only, no automotive distributors, alternators, starters, etc) are the manifolds, tstat housings, coupler, etc. The drive itself is standard Mercruiser.<br /><br />I also agree with the donor boat. That would almost undoubtedly be the easiest way to do it. Then you wouldn't have to track down any parts, except for what you might need to replace due to age or wear (bellows, gimbal, shift cable, etc).<br /><br />If the current unit is servicable with no major problems, I would run it while collecting what you will need for the conversion. Be careful though, the OMC may accidentally surprise you and last as long as you want to keep the boat. Who knows.

 

[WaterLauger]

Re: Sterndrive swap-out: stringer for Merc

Bondo mentions something about staying away from the 307's. What's the skinny? Aren't all Chev's the same?

 

[tmclendon]

Re: Sterndrive swap-out: stringer for Merc

The 307 was what we used to call a "cooking" motor; intended for low-performance cars, like your aunt ester's impala. Very mild cam, 2 barrel, etc. You can make it run, but you gotta replace a lot of stuff. <br /><br />What you want for a marine app is a heavy duty block with 4-bolt mains, if at all possible. Besides a 350 is the same physical size, probably costs about the same. For that matter they haven't made the 307 since the late 60s/early 70s so they aren't that common anymore. Now the Chevy 302 (Yes Chevy made a 302, that's the original Z-28 engine) would be a hot motor for a boat, but they are rare as heck.

 

[recess]

Re: Sterndrive swap-out: stringer for Merc

302 chevy. Now there's a blast from the past. I don't think there's a stern drive out there that could handle that one. Bought one back in the late 60's, mated it with an Edelbrock Tarantula manifold and a holley and poped the wheels off the ground of a 2 dr 56 chev wagon with a powerglide. Scared the $%^& outta me. <br /><br />350 would be preferred, but any problems with the 307 other than lack of power?

 

[Bondo]

Re: Sterndrive swap-out: stringer for Merc

The 302 really Isn't a very good boat motor, For the same reasons the 307 Isn't.....<br /><br />There's No Replacement for Displacement....!!!!<br /><br />The 302 has 1 other Problem in a marine environment... It's a Very Short Stroke motor... It Screems, But No Low-end Torque..... That motor was built for the TransAm Challange.... Carmaros are a pretty Light car.....<br />As for Outdrives... You have only 2 choices...The Mod.1, or R And the Alpha1, or MR ....(OR #3, the Alpha1-GenII) They'll Both take 300hp all day long... With the Proper Maintaince + Attention...... Much of them is Very inter-changeable...<br />I'm doing an Old Town Atlantis that I just pulled the 351 Ford, Stringer drive out..... I'm going back in with a bored + stroked 327cid....<br /> 383 stroker, thru an Alpha1 transom assembley, with a Mod.1 outdrive..... Some day I'd Love to see a 7.3l Diesel,+ a BravoIII.... But, for today, I'm building with the "Stuff" I've got laying around.....

 

[JasonB]

Re: Sterndrive swap-out: stringer for Merc

My brother half jokingly tried to convince me to drop a 351w if when we rebuilt the 302, but I have no complaints with what I have. It was rebuilt much better than stock and motivates my 19' deep vee boat to 40+. That's plenty for my use. If I need more, I can always drop on a new intake+4bbl carb. I could also change the cam timing to get more low or high end, but neither upgrade is on my radar at this point. I can cruise at 30 getting great milage (compared to my v4 outboard) and pull any skier around, probably 2 or 3 if desired. As a person who has always owned Ford vehicles (3 in the driveway now) and just generally beiing a Ford fan, having one of Ford's most popular engines in my boat is somewhat fitting. Although a 351 or 350 is likely a better marine engine as noted above, I'll keep what I have and run it till it breaks or wears out, then I'll probably rebuild just like it is.<br /><br />Bondo, I'm not arguing or disagreeing with you, just saying the're not all bad <br /><br />Now, since I have a 4.6 in my truck, wonder if the 4.6 or 5.4 will ever be released in a marine version (rumors come and go). Hmmm..... shoehorn a 4.6 or 5.4 in a boat.... now that would be interesting!

 

[JasonB]

Re: Sterndrive swap-out: stringer for Merc

Out of curiosity. I know how a 302 compares to a 351 in bore and stroke. How dos a 305 compare toa 350 since the Chevy 305/Mercruiser 898 replaced my Ford 302/888 in '77 or '78? Do they share a similar stroke?

 

[Bondo]

Re: Sterndrive swap-out: stringer for Merc

Well, I was talking about the CHEVY 302.....<br />The Ford is a Fine motor, If you're a Ford man.... It's just getting Hard to find the Marine Parts for them.....(compared to the Chevies)<br />Chevy;<br />302.. 3" stroke... 4" bore<br />305.. 3.5" stroke.. 3.7" bore<br />327.. 3.25"stroke.. 4" bore<br />350.. 3.5" stroke.. 4" bore<br />Or the Merc. 377.. 3.75" stroke.. 4" bore<br /><br />My 383.. 3.75" stroke.. 4.030 Bore....<br />The 3.75" stroke comes from the sbc 400" crank...<br /><br />Yes jason, the 305 is a Very Small Bore 350.....<br />And NO, You can't Bore it out that far....

 

[JasonB]

Re: Sterndrive swap-out: stringer for Merc

True Blue Ford man here . I didn'd realize Chevy made a 302. <br /><br />Agreed on the parts (hope my previous posts didn't sound like I was attacking you or anything, if they did there weren't meant that way and I do apologize). Ford marine parts can still be found, but nowhere near as plentiful as Chevy.<br /><br />Do the small block Chevy motors share the same stuff like the early Fords (IE, the 221 (i think), 260, 302, and 351 share many of the same bolt ons? There are exceptions to this, but generally it works out.<br /><br />I better learn some Chevy stuff, as Ford marine is a dying breed.......

 

[tmclendon]

Re: Sterndrive swap-out: stringer for Merc

The Chevy 302 was created to compete with Ford's BOSS 302 in Trans Am. Now there's a motor...Take the big (4V) heads off a 351C (Those heads had ports and valves way too big for a 351, let alone a 302, unless you wanna run about 8000 RPM) and put them on a little 302..<br /><br />Anyway, as Bondo said, neither would make a good marine motor, both were optimized for high-RPM power.

 

[recess]

Re: Sterndrive swap-out: stringer for Merc

Any problem hooking a Chev 350 to a stringer originally set up for a Ford 302. Will the intermediate housing mate up?

 

[MonkeyMate1st]

Re: Sterndrive swap-out: stringer for Merc

All bolt on Gen I chevy small block parts will interchange, except the 400 heads, they will bolt on but they have 4 steam holes, they will work on the other engines, but if you try to put the other heads on the 400, the steam holes have to be drilled.<br />Second, on the small bore small blocks, 283, 305, and 307, you have to stay with the small valve heads.