Technical 318 LA and 904 transmission

I guess when you install it you would have had to make motor mounts for it. I know about the fire wall and radiator. At least someone said there would have to be a thinner radiator. The 354 should be fun.

I have also been looking at getting one of these for transmission. Probably not from here. But this is a link for one. https://www.amazon.ca/gp/product/B005R91W2Y/ref=ox_sc_saved_title_9?smid=A3DWYIK6Y9EEQB&psc=1

 

Go to P15-d24.com.
There is a guy there that did a hemi in his 54 Dodge 1/2T. Hemi's were available from the factory in the mid 50s. Bolt in with all the right parts. The LA shouldn't present any difficult clearance issues. That said, the automatic makes it more difficult as you can't use the correct clutch/converter housing for your year. And that requires a new crossmember.

 

I wish I could find the bolt right in parts for the hemi. You would think by now there would be a bolt in kit for these trucks. Hemi, Small Block or Big Block trucks. There is for Chevy and Dodge

 

Pick ups of the mid 50s had hemi based Plymouth Polys,. Bigger trucks had 331/354 truck hemis. Not all that difficult to fab lower engine mounts & a tranny mount for the hemi with a 727, or a 318/904 for that matter. On a 354 & 727 just get a tranny adaptor from QEC (73RR), tap out the crankflange holes & use a 426 hemi flex plate. Then it bolts up.

 

Hey BamBam, about 7 years ago I bought an O/T short bed 4x4 Dodge pickup. It had a 318 with an NP435 transmission with 3.23 gears. I overhauled the 318 and reused the stock 1986 vintage heads and teeny tiny Holley two barrel carb. The only non stock item was the 340 camshaft. It had a nice little rumpy idle, the engine ran fine, but had very little low end power. It would come on somewhat stronger in the mid and upper ranges, but couldn’t breathe very well due to my shitty heads and minuscule carb. It needed better heads, a better compression ratio and better intake and carb. If your 318 is stock, stay with the stock cam. I wish I could remember the head casting numbers, but they didn’t mean anything to me because it was my first Chrysler engine.


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I drove my Panel Truck with the stock drivetrain Flat 6/3 speed for about a year and a half but as you mentioned the highway travel was not good. I did not include the IFS photo to push you or anyone in that direction. It was to show how much room the engine bay has. I added the IFS to get better handling and get her low. That was my way.

 

The highway running is so I can go faster then 60 mph with pedal stuck to floor. My truck has a 4 speed but one is bow low. The stock rear end has 4.10 gears in it. I would like to put 8 3/4 rear end in it and mustang 2 front end. I have wanted to do this for about 2 years now. I have the old split rims on it still.

 

Like Gene Koning says, run the 340 cam and double roller timing. 340 valve springs too. 360 cam is not a bad choice either. I have six 340's and some 318's and have run 340 intake, cam, timing, windage tray, valve springs in a 318 that we told people was a 340 (track rules for that car). Used small chamber '67 318 heads. Also turned the pistons backwards for a straighter shot. Engine ran like crazy! No, not as good as a 340 but still kicked their butts. Windage tray is cheap HP and NO detrimental issues. Edelbrock D4B intake if ya can find one is great for 318's too.

Dave

 

There were several companies that made kits to install small block, big block, old hemi, and 426 hemi motors in these Dodge/Fargo trucks. Finding one of those old kits would probably be pretty hard these days. Most of those kits placed the motor forward so it was centered over the front axle, manual steering with wide tires was a chore to turn at slow speeds.

I've built a few of these trucks and on all of them I have moved the motor/trans back enough I needed to cut the firewall. Its more work but it sure makes for a better balanced truck.

We only left the beam axle in one of those trucks, the cost to rebuild the original obsolete brakes was more then we would have spent upgrading to disc brakes, that was the last beam axle we used. By the time the other trucks got to us, the springs were shot with groves wore in the longer leaf by the shorter below it, and the steering boxes were usually in pretty sloppy.

The 4th truck (a 49 Dodge) is sitting in my yard, the sheet metal is currently sitting on a modern 4x4 frame, I haven't looked into the drive train placement yet (318 Magnum and its OD 4x4 trans that matches the frame). It will be a near future project. Gene

 

Well of course its not good, beatup worn out flathead 6 with no more HP left. Wrong gearing too. IFS well thats a personal like I suppose. These trucks when some leafs are removed and shackles bushing new ride very well and are much lower. But again individual choice. Your 6 was flat out worn.

Again you have the wrong gearing and your 250 is old and tired.
318 and a A904 will liven it up.
You already been hangin out at P15d24 and no you can make these trucks highway cruiser friendly.
Many of those guys have hopped up flathead 6s, OD transmissions and appropriate gearing.
On your HEMI idea go see Bisquick gor more info has he did just that.
Your truck with a hopped up 250 or better yet 265 an A833 or some other trans with correct rear gears will give you a hell of lot more than you have now .
But its your project and you know best on what it is you expect and want. Some guys just have to go V8 or IFS. Like some comments above.
Dont worry you dont need 75 to 85 mph in Manitoba as highway speeds are some of slowest you can find.
Every time I see a vintage car or truck they are 90% of time putsin at 90 kmh...lol
Here are some hot flathead 6s. Good luck on whichever way you go.

 

Here are the photos finally sorry took so long, don't hate me for the electric fan crap, I hate them and they are getting pulled off soon when I get the rad flushed and boiled for 10 year maintenance check.

Boxed frame rails help strengthen things up, 1/4" plate and some pipe inside the mounts for easy slide tube so the bracket doesn't crush when tightened up. works like a charm.

 

Why don't you leave the 4.10 rear end as-is , But use an A-518 trans behind the 318.
You're swapping the trans anyway!
The O/D of the A-518 is 0.69:1 so combined with the 4.10 rear it would have an overall ratio of 2.82:1
With 28" tyres you would be cruising 2200rpm at 65mph

Leave the 318 stock but use a decent rebuilt 2-barrel carb [add electric choke] and a decent free-flow exhaust [a 2-1/2" to 3" big bore single exhaust]

It would be quite sharp around town because of the lower rear-end and a good highway cruiser

 

O/D only helps on the highway, would still get hammered MPG wise in town. 1st thing I do with a 318 is toss the intake & get a 4 bl on it.

 

only if it is held in 1st gear
With the lower ratio rear end, the trans will upshift earlier [load and governor speed determine this]

30 mph with a A518 trans in 3rd gear with a 4.1 rearend and 28" tyres = 1476 rpm
30 mph with a A904 trans in 2nd gear with a 3.08 rearend and 28" tyres = 1607 rpm

45mph with a A518 trans in 3rd gear with a 4.1 rearend and 28" tyres = 2214 rpm
45 mph with a A904 trans in 2nd gear with a 3.08 rearend and 28" tyres = 2411 rpm

65mph with a A518 trans in 4th gear with a 4.1 rearend and 28" tyres = 22o6 rpm
65 mph with a A904 trans in 3rd gear with a 3.08 rearend and 28" tyres = 2402 rpm

Across the range there is only about a 200 rpm drop [which isn't much] but the 4.10 rear will "wake up" off the line, and haul heavy loads better.

If the OP needs the parking brake from a later rear-end, then he might be stuck with the rear end swap option [and keep the A904 he already has]
A 73-74 Challenger with a 318 Auto had either a 2.76 or a 3.23 rear end [the OP could use the later with larger diameter truck tyres]
In stock 2 barrel configuration ,they all drive great. I had a 318 auto in a 1970 Aussie Valiant [Dart] that I drove the wheels off that thing when I was young

 

If you are going to use a Mopar OD auto, I would use the A500. Several reasons, 2.74 vs. 2.45 low gear, takes a lot less horsepower to turn than an A518. Most all A500's had the lockup converter-better for gas mileage.

 

Only one thing wrong with your posting, if that 904 isn't in 3rd gear by 30 mph, your kickdown needs to be adjusted, or you need to put the shift lever in drive rather then in 2nd. Its the same deal at 45 mph, the 904 should be in 3rd gear long before 45 mph. Maybe you have your numbers flipped. Gene

 

If a A904 trans changes into 3rd gear at 30 mph with a 3.08 rearend and 28" tyres = 1108 rpm [This is below the stall speed of the converter and usable torque curve of the engine]
It would probably slip the converter resulting in the same RPM as the 4.10 rear end ratio [1476 rpm]


If the A904 is in 3rd gear by 45 mph with a 3.08 rear, then the A518 should be in 3rd gear by 33 mph with the 4.10 rear [both situations have the same driveshaft speed and a 1:1 ratio 3rd gear]
An A518 can easily be programmed to change into 4th at 45 mph with a 4.1o [using oil pressure and vacuum switches]

45 mph with a A904 trans in 3rd gear with a 3.08 rearend and 28" tyres = 1663 rpm
45 mph with a A518 trans in 4th gear with a 4.1o rearend and 28" tyres = 1527 rpm

All I did was an overlay of total ratios to prove that lower gears don't necessarily affect fuel consumption due to excessive rpm.
The O/D of an A518 is equivalent to changing from a 4.10 rear end to a 2.87 rear end [a 3.08 being slightly lower, but 1-2 gears in a A518 are also slightly higher]

The whole thing is an exercise in futility if the OP needs to swap the rear end to get a park brake.[he might as well keep the trans he already has, and change the rear end ratios]
A518's and A904's dont have a park brake drum in the tailshaft.

 

Still have an issue with your numbers. Back in the 70s (yes I lived back then), it was standard procedure for Mopar to put a 904 behind a 318 with a lockup torque converter and 2:76 rear gears. The fact is, some of the 5th Ave even had 2:45 rear gears, and those 904s were in 3rd gear before 30 mph as well. They were always in 3rd gear by 30 mph and if you were lucky, the lockup didn't lock in until 35 or closer to 40 mph. The next reality is it is pretty hard to find a v8 904 equipped car with a gear set having better gears than a 2:94 from a car that was built after 1974.
The cars were not very performance oriented, gas mileage was the main theme so Chrysler did indeed build millions of them that functioned well past 100,000 miles with a 318, 904, 2:76 (or 2:45) gears that were in drive before 30 mph.
If he is installing a V8 904, the odds are it has the lockup converter and unless he changes things inside of the trans, it will be in drive before 30 mph, rear gear not even a consideration.
And I agree, it probably won't matter anyway. But I like to see "facts" be accurate. Gene