Slightly O.T. but your area of expertise.

351pacecar

Founding Member
Jul 2, 2001
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Hudson, Wisconsin
I am looking at getting a boat with a '72 ford 302 in it with oil that looks like a cappucino (investigating the cause, believe to be a cracked block) for dirt cheap (because of the junk motor) and I am wondering if an '88 5.0 that I still have sitting in my garage would bolt up correctly as a replacement. The 5.0 was originally slated to go into a '69 stang project that was aborted, so it has all the parts to run carburated with a mechanical fuel pump on it at the moment.

My main problems I think are whether the bolt pattern on the bellhousing is the same between 72 and 88 (I forget when they changed) and what to do about the odd marine flywheel I will need with a 50 oz imbalance but I can figure that out on my own. They are sometimes identical to the car ones and I hope i can just use the stang flywheel with the funny marine coupler bolted to it. (no clutch so it just physically bolts something to the clutch cover holes that the input shaft goes into) I am hoping the huge exaust manifold things will bolt on the same and flow well enough also, marine headers are over $1k. Anyone think of any other trouble spots?

Or maybe I should just try and fix the 72, its in for repairs right now (iam a marine mechanic) and I discovered the oil issue but havent had time to investigate yet so I dont know if the block is cracked or what. Its an 188 hp 2bbl holley carb setup so I dont know if it relates to any of the motors the mustangs got or whether or not the head and cam are car pieces.

Itll be interesting to do if nothing else.
 
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other than the balance part i can't think of any reason why the swap wouldn't work. the exhaust manifolds will bolt right up.

ok i did think of something that could hurt you as far as the swap, is the 72 engine currently in the boat set up for standard or reverse rotation? if it's standard you should be ok, if it's reverse rotation you could be in big trouble.
honestly that would be my main concern, i don't think the balance isue should be that big of a deal either, i'm pretty sure that both mercruiser and volvo penta both used the later model 302's at some point with the correct 50 oz. imbalance.

i used to be a marine mechanic when i lived in Austin, though technically i was considered a mechaninc's helper i could anything the "real" mechanics could do except for wiring and we only had one guy that did wiring anyway
 
I jumped to the conclusion that it was a cracked block because of the boats history, its the ferry for a doctor friend to get to his sailboat, and wasn't winterized at least one year if not more resulting in freeze plugs getting blown out. Plus it went half underwater at one point this last year due to rain and a bilge pump not working for some reason so that could also play a role. As soon as I get another starter on it and get it started I can determine if its a fast water contamination or a slow one and try to figure out where it came from.

Its standard rotation iam sure since its only one engine. If it is compatible I would also pull the distributor off the old engine and pop a new gear on it for the 5.0 roller cam, then just switch around the firing order to the newer specs. That way id keep the points and not bother with electronic which sounds crazy but its alot easier to fix points than electronic ignition in the middle of a lake. If its anything like a 4.3 I just swapped I can actually use the mustang car flywheel, Ill hafta see about that, the boat ones are sometimes heavier.

Another problem I have noted is that the original '72 manual and the engine both agree in large letters that leaded gas is required and I doubt that the engine has been modified otherwise. I dont imagine anyone bothered to put leaded gas in it for the last few years so id imagine the valves are going to need some work. I will be checking on that too, sometimes this doctor friend pleasantly suprises me, other times he screws the cabinet he is assembling to his $30k hardwood floor (not kidding)
 
Pulled the plugs, cylinder 7 and 8 have what looks like cream in them plus alot of water, engine was starting to get hydro locked from them, never seen so much oil/water contamination from a head gasket before. I noted that one of the blown freeze plugs is right between 7 and 8 so who knows what ill find. I think I will buy the boat assuming the motor is junk and hope for better.