55 C Series 318/904 Swap Blasphhemi Not

[55 Fargo]

Hey all, although this site is predicated on the almighty Chrysler Flathead 6 engine, there are tymes when a swap to another powerplant is desired.

I still firmly believe Chrysler flathead 6s are 1 of the greatest engineering marvels of the early 20th century. These engines continue to give great service records well into the early 21st century.

Okay here's the story,

Early this spring it was very evident my Fargos 228 engine was either just getting to tired, or needed a swap to 265, rebuild or serious gear swaps.

On the highway, against a brisk wind with vacuum gauge, it was real indicative of both sucking fuel and super low vacuum at speed.

In fact, getting to 60 mph was a chore, I attribute this to both, 3.23 gears and a weak engine.

I needed to make a decision on either I rebuild a 265 or swap in a low mile 318 I acquired for next to nothing from a 1986 Fifth Avenue Chrysler.

So after a few weeks consideration a decision was made to swap in the 318/904 combo.

I went to work on prepping this job, flathead 6 removal and getting 318 ready to go in it's place.

A good friend helped me swap, fabricate and install engine and trans mounts, cross member etc.

This went fairly smooth, and all was created to allow a swap right back to flathead 6 if desired in the future.

A driveshaft was sourced and cut to size, external trans cooler, and a used Mr Gasket shifter.

Exhaust is cobbled together and needs to be constructed properly at some point.

Engine runs great, some bugs needed to be ironed out, a few still linger.

Performance difference with a 318 versus a tired flathead 6 is night and day.

Getting to speed in highway is very fast.

Its no 300 hp engine, but a whole lot more snap.

Some pics.

[Jim G]

Heresy!!! (OK now that's out of the way ) Glad you stuck with mopar powerplant, and given where we live (I'm next door to you in the easy to draw province) it's nice to have a reliable vechicle if you want to go any distance. And now if you break down parts are a lot easier to find and get back on the road.

[55 Fargo]

3 hours ago, Jim G said:

Heresy!!! (OK now that's out of the way ) Glad you stuck with mopar powerplant, and given where we live (I'm next door to you in the easy to draw province) it's nice to have a reliable vechicle if you want to go any distance. And now if you break down parts are a lot easier to find and get back on the road.

I agree on roadside issues and parts.

Truck is quite quick and gets to 70 plus mph rather quickly.

It cruises along beautifully at 65 mph and fuel economy is or seams better than a flathead 6 is.

Because this engine was a 1986 LA series it was a "Lean Burn" setup.

I converted it to pre lean burn, ignition, fuel system and no emissions except a PCV setup.

I did change out exhaust manifolds, in doing this I tapped and plugged smog holes on each head.

The heads are a cast"302" type heart shaped CC. Its higher in compression too at 160 to 170 per cyl.

Its a whole different animal now...

[Old CWO]

It looks like it fits in there very nicely.  While I certainly appreciate the flattie, there's nothing wrong with a little more HP/TQ under the hood either.  I like your engine choice:  not a path of least resistance GM, not a gold plated early hemi and not an over the top rumpity cam'd 440.  Simple, reliable and just enough engine for good pep without overpowering the rest of the truck.  Small traditional OHV V8s really can be a great compromise of performance, economy and cool factor.  Not to mention a good dual exhaust on a Mopar small block just flat out sounds great.

 

Any future plans of EFI or staying tried and true with the carb?

[55 Fargo]

18 minutes ago, Old CWO said:

It looks like it fits in there very nicely.  While I certainly appreciate the flattie, there's nothing wrong with a little more HP/TQ under the hood either.  I like your engine choice:  not a path of least resistance GM, not a gold plated early hemi and not an over the top rumpity cam'd 440.  Simple, reliable and just enough engine for good pep without overpowering the rest of the truck.  Small traditional OHV V8s really can be a great compromise of performance, economy and cool factor.  Not to mention a good dual exhaust on a Mopar small block just flat out sounds great.

 

Any future plans of EFI or staying tried and true with the carb?

No will either stay with BBD 2 bbl or possibly 340 intake or aftermarket with small 4 bbl carb.

The beauty is I could pull this and go 360/727 if i so felt inclined. At this point its plenty of power for stock suspension and brakes...

[Old CWO]

38 minutes ago, 55 Fargo said:

No will either stay with BBD 2 bbl or possibly 340 intake or aftermarket with small 4 bbl carb.

The beauty is I could pull this and go 360/727 if i so felt inclined. At this point its plenty of power for stock suspension and brakes...

.

The old school 2 bbl surely keeps the simple/reliable vibe going - works fine and lasts a long time.  Nothing to complain about there...

 

Keeping the power a little conservative on an old truck is a wise call; better to be safe than fast.  I think a slant or V6 just isn't quite enough gain over the original plant for the effort involved so a 318 should fill the bill nicely.  I also see that engine as a "gateway" for other potential future upgrades like AC, power steering, etc. if so inclined.

 

It's cool, I dig it.

 

Maybe the old 228 can live on powering a welder, generator, pump, tractor or something?

 

 

[55 Fargo]

2 hours ago, Old CWO said:

.

The old school 2 bbl surely keeps the simple/reliable vibe going - works fine and lasts a long time.  Nothing to complain about there...

 

Keeping the power a little conservative on an old truck is a wise call; better to be safe than fast.  I think a slant or V6 just isn't quite enough gain over the original plant for the effort involved so a 318 should fill the bill nicely.  I also see that engine as a "gateway" for other potential future upgrades like AC, power steering, etc. if so inclined.

 

It's cool, I dig it.

 

Maybe the old 228 can live on powering a welder, generator, pump, tractor or something?

 

 

Yes, I concur on being "wise" on how much power is limited on non reinforced C channel frame and old suspension.

The suspension if in tip top shape, meaning springs, shackles bushing front end, steering etc. Can no doubt handle a lot more than my 318 can put  out.

But steering and handling on rougher or winding roads will be a handicap Im sure.

I have lots to do yet on this old girl.

Pull all springs, redo bushing and shackles. I may remove 1 spring per pack, to soften and lower truck a bit.

I also plan on a sway bar on both front and rear too.

Will also install 3 link seatbelts, roll cage not necessary...lol

[Tooljunkie]

I like it. And starter is still in the right place!

after doing all the chassis work on mine,i wouldnt go more than a small block dodge in mine. I am suprised how flimsy the frames are. Now that its all behind me, and it runs, i will be on the lookout for another teener. 
 

 

[55 Fargo]

5 hours ago, Tooljunkie said:

I like it. And starter is still in the right place!

after doing all the chassis work on mine,i wouldnt go more than a small block dodge in mine. I am suprised how flimsy the frames are. Now that its all behind me, and it runs, i will be on the lookout for another teener. 
 

 

With anything over maybe 250 hp would reinforce frame.

I have no issues with steering and handling if your sane with speed and road conditions.

Even with a frame ir front clip swap, you have old school truck body in collisions.

A good friend if mine had a 59 Dodge swb with hi perf 360 and 4 spd. It was super wild and flex that C channel frame like crazy. But it was deadly quick.

[59bisquik]

Looks great!

[55 Fargo]

9 minutes ago, 59bisquik said:

Looks great!

It really does make the truck a Hotrod over a farm truck 

[59bisquik]

Pretty sure we chatted about this already! ? 

[55 Fargo]

9 minutes ago, 59bisquik said:

Pretty sure we chatted about this already! ? 

Gotta redo all springs, shackles bushing.

Wanna include sway bars and maybe a steering damper...

[59bisquik]

I would love to see what you come up with for a front sway bar. That is on my list!

[55 Fargo]

9 minutes ago, 59bisquik said:

I would love to see what you come up with for a front sway bar. That is on my list!

And is it really necessary?

Hiw do you feel about steering damper.

My steeri g box does have slightly too much play..

[59bisquik]

The damper will just mask the problem. I think fixing the box would be more important.

 

As for the sway bar, I plan on doing front and rear. With the speeds I drive, I think it would help with handling. The rear is pretty easy and I have an Explorer bar I was going to use. The front I haven't figured out yet. 

[55 Fargo]

Yes of course on box. But the VW big steering damper is  used a lot on hotrods. It apparently works real well with steering control especially with bias ply tires.

Don't think getting these boxes rebuilt is real easy. And the Canadian trucks used different steeri g boxes to boot.

Here's the deal, these trucks with stock suspension are pretty good when in top shape and roads are flat and smooth.

I have driven mine plenty on gravel roadsat 50 to 60 mph..

Had mine up to 80 mph yesterday, and it had a lot more.

Not comfortable driving at that speed 

I like 60 mph. But i can get there way way faster over a flathead 6....lol

 

[Tooljunkie]

Would think a sway bar fom something like a full size 4x4 may work. Any with a front leaf suspension. 

[59bisquik]

I run at 70-75 on the highway but also run low profile radials. Sway bar is on the list after getting my Hilborn working. Hopefully you will figure it out shortly!