If you have the pan off you might as well Plastigauge the mains.

Yep!

Oil pans don't interchange

Word ....

There is a chance that a new pump will get you going, have changed the rods and mains in the car after bypass failed but it was a BB and crank was still good.

If you do pull the pan you'll see the pickup screen right off the bat & it might be majorly obstructed. Holler how it turns out for you.

Never run a single grade oil. It's 2017.

What's in it for oil?

Don't know where you live, but a 10w40 is good to about 15* F.


Never run a single grade oil. It's 2017.


A 20 winter grade oil (as in a 20w50) is good to about 32* F.


Never run a single grade oil. It's 2017.

I didn'the mean it was ok. I was really surprised that GM would state that it was ok in their owner's manual. I figured it needed bearings.

Dan, it wasn't aimed at you, pretty much everyone before you said it's OK or maybe need thicker oil. To my mind that says it's still OK.

OP, You have to pull the pan to see the oil pump.

While you're in there pull the #1 rod bearing and I bet it's trashed. To me that means you need new parts.

Don't go putting bearings on the crank until you have miked it and found out what it really is.

IMHO you start looking for a 1985 and up Fifth Avenue and pirate the engine out of it. Slide a 360 hydraulic roller in it and dress it with your original parts and keep on trucking. Those engines are nearly new at 100K miles. No ridge and you can still see a little crosshatch. You'll replace the bearings and wonder why. Plugging the AIR holes in the heads will be the most demanding task and that's easy.

R.

There is nothing wrong with straight weight oil no matter what year it is.

Lots of opinions here but it's fair to say you're faced with a few issues;

Engine has a lot of miles on it. I suspect the new oil pump may have gotten you further down the road, but chances are good the mains are pretty well worn out.

The path of oiling can make or break you in a situation like this. With loose clearances you're losing control of the oil along the way. Everything further down the path of the oiling system gets progressively less oil, which means more wear, higher temps, etc.

Some engines will indeed run a long time with worn out bearings and/or low oil pressure, but others won't. I've run small block Chevy's with the gauge bouncing off zero for miles and have an AMC 360 with all the mains well into copper and yet it runs fine. I've had poly 318's go a long time but not had as much success with LA engines. Perhaps it's all a matter of chance.

I'd think you'd be getting some lifter noise by now.

Regardless, it seems like you're at the point where reliability of the car is a real concern. If you're like me, the last thing you want to have happen is a breakdown somewhere on the highway, or worse yet out in the country and be stuck there, having to leave your car to go get help.

By the way I've a 67 Fury III 4dr hardtop too and love the car. Have had it for years. Great running/driving car and it's tough to have any 4 dr look as good as these do.

Thanks for all the replies.
I was at the East Coast Indoor Nationals yesterday and talked to 383man and a couple of other folks about the engine, including a rep from a shop that does restorations.
The guy from the shop said he'd recommend a swap over a professional rebuild, given that it's a stock 318 and I'm just looking to be able to drive the car again. In fact, there's even a 78k-mile 318 sitting on a stand in their shop right now that came out of a customer's '68 Coronet (which is getting a stroker installed). The catch is that the compression is down on that engine, so it needs to be gone through anyway.
I don't know about the late-318 swap idea (the Fifth-Avenue scenario described above). An early LA 318 like mine is 230hp, those 1980s smog engines are like 130 or 140. Granted, a loaded M-body is probably pretty close to the weight of my '68 Fury convertible (hell, my '76 B-body was heavier than my '67 Fury, according to the MD MVA).
The more I think about dropping the pan and pulling main caps, the more I think "It's got over 204,000 miles on it, the bores are probably barrel-shaped, the bearings are probably shot and I know it's got at least one bad lifter (which collapses and then pumps back up--the noise comes and goes)."
And so I have this role reversal on my two toys: The '68 convertible, which has run whenever I've wanted to run it for 22 years, is a big paperweight, while the '67 4-door, which has had me chasing problems for most of the 10 years I've owned it, can suddenly be driven at will.
I'm gonna keep looking for engines and hope I can find one that's not too far away. I'll have to rent or borrow a truck to retrieve one, unless I find one with a really helpful seller.
Funny story: I was telling the owner of the comic shop I use about all this, and how there's a 318 in the Moparts classifieds right now that's cheap, but it's in Michigan. His reply? "Wait till I go to this convention in Novi, and I can load it in the (rental) truck when I come back." Nice offer, but a little nuts--also dependent on him selling enough at the con to make room for the engine.

Remember those newer engines are rated net hp, vs. yours rated gross hp. Dress the newer engine up with your intake and carb, plug the air pump holes in the head and you won't be down much at all, if any. The camshaft events are different for smog but the lift and duration are very similar to your original cam. One of the newer pre magnum engines will also have roller lifters.

Retrofit a newer magnum with 230 net hp and you'll see a nice performance and maybe mileage bump as well. 2¢

Robert

Imo, if your going to do a swap, look for a magnum.

There is an 70 318/904 combo intact and stock with 39k miles on the small block engines board for $350.. can't beat a deal like that. Check out out.

Time for an overhaul for sure, at the very least...

Sorta surprised no one mentioned this one:

I had the same thing happen on a 73 charger I had back in the 90's. Drove it that way for 5 years- as a Daily Driver. Finally bought a Ramcharger so I pulled the engine/trans in the Charger for a rebuild. Dropped the pan and- #3 main bearing- the one with the thrust surfaces- the tolerance on those thrust surfaces is supposed to be like .010" (going on memory here guys), mine was like 1.0" . Yeah, nearly not there. Oil was just flowing out of there. Chewed up the crank pretty good. So, out it came and it was rebuilt, etc...etc..etc.

If you're going to go through all the work of swapping engines might as well find a later model 360 magnum. Same dimensions but with the added bonus of more cubes and much better heads/cam/block/etc. You'll have to use the timing cover and cam and eccentric from an earlier engine to use a mechanical fuel pump, but an inline electric will tame the gasohol blues in a street car anyway. 360 magnums are dirt cheap and in abundance at most junkyards. Just look for any 250 series truck and you'll find one.

IF it has to be a 318 the 5th ave suggestion works- the 85 and ups had roller cams and the good swirl port heads. They can be adapted to about anything. But given the choice, I'd look for the magnum.

Just my pennies,
Good luck with it.

CC.

Saw it and saved the info on my phone. I was going to call yesterday (Monday 12/5) but I ran out of day. Kinda wonder about shipping an engine from CT to MD, though. I don't own a truck, so retrieving it would mean borrowing or renting one, getting a hotel room for the night, and driving about a thousand miles round trip in 48 hours.

(Granted, I did 800 miles in 27 hours when I bought this car out of NC, but I was younger then.)

Do you have a car with a trailer hitch. If you do than just hit UHaul for a smaller type trailer.