What should I replace my 318 with?

[truckluvr]

Well finally took the new... 67 d100 stepside on a day of fishing with my boat. Unfortunately by the time I got it home it was huffing and puffing. I think the LA318 has some real problems. I'm getting exhaust bubbles in the radiator, there seems to be a constant well of oil that puddles up on the intake manifold and today I pulled the plugs and 5 of the 8 are nearly fouled with black soot. So it's hemoraging oil into the cylinders some how.

I like the 318's economy and I have a source for an 86 fifth avenue 318 roller motor with only 86K out of a wrecked car for $300.

OR... I have a complete 74 motorhome 440/tranny with 43K tucked in the garage (my wife wants me to install this...)

OR... I have a 360 motor that I could overhaul

OR... I have crank/rods/pistons to build a 408 stroker out of one of the 360's I have...

[digdoug]

This is an easy one...make the wife happy!

[truckluvr]

Will my front suspension handle the weight of the 440? If not what can I do to remedy this? Can I swap springs out of a 3/4 ton or something? Who sells BB bracket / mount conversions? Seem like an awful lot of motor for this little truck just to pull my boat.

[surfnuke9]

440. Too much is never enough.

[truckluvr]

Okay 2 votes for the 440.

[MOPAT]

What trans?
360/408 might have flywheel or clutch issues. If you have a NP435 what is the input shaft spline count?
Internal balance vs external balance issues.
440 -- finding a big block hydraulic clutch bell housing is expensive. Changing to manual can be a pain.
Going with the 86 318 would probably be easiest and cheapest.

[surfnuke9]

he said he has a low mile 440 and trans sitting in the garage, hence my vote for the 440.

[MOPAT]

Just saw that he was thinking 440.
Then I guess it is just motor and trans mounts. IF he isn't already running a 727.

[BigBlockDodge]

I vote 440. like surfnuke9 said "too much is never enough!" There is nothing wrong at all with a chrysler small block, but theres nothing like having that extra power/torque under the hood for when ya need it! another plus with a big block is how easy they are to work on (not counting spark plug access. although it's easy when you get the "feel" for it). no antifreeze passages in intake, oil filter in front for easy access, external oil pump, 4 bolt water pump, distributor in the front...etc. The only big downer with a big block is worse gas mileage, of course. But I had a 318 in my W and recently put a 383 in it. The best mileage i got with the 318 was 12.5mpg. now the best so far has been right around 10. But it has soo much more power! And 12 is pretty crappy mileage anyways...

[truckluvr]

Currently the truck has a good solidly rebuilt 727. You have a point about 318's not getting good fuel economy. My old 77 d250 with a 318 and 4.10 gears got maybe 12-14mpg highway and about 7 - 8mpg towing. I replaced it with the 78 powerwagon with a 440 and same gears and it gets 8-10mpg highway and 7.5 - 8 towing 10,000# (half throttle too). This truck has 3.55 gears. I could put in 3.23 gears and probably offset the economy diff maybe? Just wondering if the current 2 row radiator will handle the cooling? Do these trucks handle ok with a big block?

[runcharger]

440 but it will take a bit to install. Second choice would be the roller 318.

Sheldon

[truckluvr]

Well If I do decide to go with the 440 what things will I need to change? Are headers an option or do I need to stick with stock exhaust manifolds and which style fit?

Oh by the way my wife says she likes how you guys think and if I don't put the 440 in she's gonna put it in a Pontiac Firebird to get back at all the people who put chevy motors in old mopars. Ponipar/ Mopiac?

[MOPAT]

B/RB motor headers have a clearance issue with the bell housing motor mount as I recall.
I could be wrong again though.

[truckluvr]

So going from an LA318/727 to a 44/727 the only thing I need to change is the motor brackets?

[digdoug]

If you still have the motor home brackets on the 440 they will work. You will have to change the rad.,exaust, and build or find a longer throttle linkage and lengthen a few wires.

[nfury8]

74? Any idea what the compression is on it?

[OregonDodgeboy]

Your wife is a keeper. Go with the 318, since I REALLY want to see her spanking and p g off the GM purists at the track with her 440 powered Pontiac.

Seriously though, the 440 is a blast. I always got 11-12 combined city and highway with mine. Towing hardly affected it. Only heavy towing or over the mountain passes made it drop below 9. In fact, I got 14 with it once from San Fran to Portland with a moderate load on it. Maybe all the downhill helped?

But honestly, the 318 will do all that too, and get you better milage. The 318 in our 67 was a steady 14.5 combined, 16 highway. Hauled some outrageous loads with it with no issues. If you haul very little and aren't needing a hot rod, go small block. Save some coin on fuel. If you have to top the big hill with the boys, first, while towing your toys, the 440 is it. It just depends upon what you will be doing 80% of the time with it. Set it up for that, and it will cover the other 20% because it's a Dodge.

[truckluvr]

Well I still have the brackets and mounts still on the 440 so hopefully they will work to save me some coin. all 440's were the same compression from 71 till the end of production. The difference with this one is it has the rare motorhome heads. 213's I think with the extra water passages between the middle exhaust ports for better cooling plus most 74 440's had either double roller chains or timing gears and the last one I rebuilt had 6pk rods and moly rings. Not sure what all this one has. As with most of Ma Mopar stuff it's a crap shoot what you'll find.

Went ahead and pulled the top end of the old 318 off to see what was causing problems and the head gaskets crumbled apart so I couldn't tell if they were blown. The lifters are starting to get a little worn and there were no valve stem seals left but the valves seal tight when I test sprayed carb cleaner in the intakes and exhaust ports so that's good. I'll put new stem seals in after I hot tank everything, and put it all back together with new gaskets and see if that helps. If not then I'll just have to flip a coin as to what I'll do on the repower.

[hampstead38]

Engine selection should be driven by use. If this truck's primary purpose is to pull a fishing boat... do you really need the 440? I guess I should ask, how big is the boat? The gearing in the Sweptlines is conducive to pulling (some would say up to and including stumps). If you pull steep hills or heavy loads, the 440 will make the work very easy... but that's not to say the 318LA is not capable. In fact, I think the truck is capable of pulling and hauling enough on the drivetrain side to scare the beejesus out of some of us on the braking/suspension side.

[truckluvr]

Well I kinda figured the head gaskets were toast so I freshened up the heads, and installed an Edelbrock SP2-P 318 intake and rebuilt a Carter 9811 thermoquad just to see what that would do and even with a worn cam and lifters she runs pretty darn good! Tows my 1974 19' Starcraft boat up the hills pretty well too. fuel economy is around 12mpg which kinda sucks but I'm also dealing with a stock shortblock and exhaust manifolds for now. Think I'll save the 440 for something else... . Eventually I'd like to build another 408 stroker (which I have all the parts for) and maybe bolt it to an A-518 tranny for quality cruising. But for now I'm just happy the truck is reliable transportation until I get my master bathroom remodel finished! (what a pain in the a$$)