Ok, fellas. I'm new here and new to pretty much anything mechanical beyond oil changes or the odd fuel pump.

I have a 1987 Dodge D150 with a carb'd 225 slant six that is .... Tired. Truck is a four-speed, no idea what kind. No idea what rear end it has either.

I really want to do a 318 swap, but since I'm new to this sort of thing, I'd appreciate some hand holding. Can someone break it down Barney-style for me?

I am assuming I will need: Engine mounts (do the frame mounts need to change, or just the rubber mounts?) Radiator/hoses, alternator bracket, flywheel, bellhousing, drive shaft? Also, with a truck that vintage, what sort of wiring harness am I looking at? I don't guess the truck has much in the way of an ECU, but I need to know before I go ripping stuff apart.

For what it's worth, the motors I have been seeing around that run are generally carb'd, so I'd likely go with that for the sake of sanity.

All help is much appreciated. Thanks.

 

Not to familiar with trucks or the 6cyl. but my suggestion is to look into a 360 instead of the 318, should be able to get one for the same price as the 318 and make a little more power with it and it should be just mabout the same swap as the 318

 

Your truck had the option of a 318 from the factory. It had a carburetor if my memory serves me correctly. This would be a fun swap.


For a good swap that has respectable power I would look for a 5.2 magnum motor. Search my post, I did a lengthy one on the swap parts. E pump, distributor and intake. You can use all the magnum front accessories.

The 5.2 motors are NOT expensive in the bone yards. They are great motors!! The 5.9 just gets chosen more. Swap info is the same. Plus the 5.2 in the magnum was internally balanced. You dont need special flex plate or TC weights.

I need to do some research on what tranny came with the 5.2 for your year? I think there was a manual option too.

So you need.

used magnum 5.2 motor with accessories and serp belt installed and exhaust manifolds and flex plate. Check compression.
Dizzy
intake with vertical bolt pattern for mag heads
motor mounts for 5.2 for 1987 D150
used carb
Tranny
new linkage for tranny
driveshaft length?
tranns crossmember
speedometer gear
used taurus or lincoln mark 7 E fan
radiator hoses to fit
new PS hoses to mate new pump to box
possible custom AC hoses if you have air.

I'm sure I'm missing stuff but that should get you started..

 

Thanks for the help man. I like the idea of the Magnum motor, but would it be easier (cheaper) to use a lump from around the same '83-'87 period? Or are they crap?

Also, what kind of power do non-Mag 318s make and how much does a cam/intake/carb/exhaust upgrade wake them up?

 

Easier? No. Are they crap? Hell no! LA 318s are great motors. Is the LA 318 engine better than the 318 Magnum engine? As designed by the factory, No. Sorry.. Magnum motor are nothing more that LA with upgrades for power and oil control. That is exactly how and why they were designed.

On an engine swap, regardless of the make, the small items and accessories are the killer price wise. Until you do one you don't realize how much the little stuff adds up.

All things being equal it is much easier to wake up a magnum motor than an LA motor. Why? Magnum cylinder heads flow more than any factory LA 318 head. And a roller valve train will make more power than the same cam in a non roller configuration.

Plus the newer mag motor may need no machine work and give you many more miles. Any LA 318 motor now sitting idle will need machine work. ( Well it may not but I wouldn't install it without cracking it open for checking.) Think about it? LA motors are 25 plus years old minimum.

Ive NEVER done a 318 into your type truck. I have done many 5.0FI Ford HO motors into classic ford 6 cylinder trucks and I took the trans, all accessories, motors, etc.. some times I took the whole donor car. I did these swaps when I was young ( and dumb) and they were not hard.

Keep searching the web and figure out what you want for HP, transmission etc.. Then do a build sheet and price stuff.

 

PK1 - Are the 5.9L Magnum internal or externally balanced? FYI - An 87 D150 w/318 was carb as the next year is when they came out with the TBI units on them.

Arich - You could have an NP435A or an NP435L for a transmission. The NP435A have a gear ratio that follows:
1st - 4.56
2nd - 2.28
3rd - 1.31
4th - 1.00
R - 5.64

The NP435L would have the following gear ratios:
1st - 6.68
2nd - 3.34
3rd - 1.66
4th - 1.00
R - 6.06

When driving, you will notice a huge difference in between 1st gear of the two trannies. The NP435L will just want to crawl and allow the motor to rev high without going very fast. The NP435A will go much faster in first gear and act more like a car tranny.

Now this is just an assumption as you could have something completely different. Here is a picture of what an NP435 ("A" and "L" models look the same on the outside).

 

All mag 360s were externally balanced. Too much money to add heavy metal to the cranks in production. So they just balance at at the ends. Weights on the the TC / or flex and front dampener is counter weighted.

All mag 318s were internally balanced.

Great info on those trannys! Any idea what they are rated for ft lb wise?

 

So the Magnums are balanced how the LAs are (318 - internal, 360 - external), thats good know know.

The NP435 trannies are one of the big HD trannies that can handle a good amount of power. They were used by the three big companies in 1/2T. 3/4T, 1T and bigger trucks. People in the four wheeling world love the NP435L and NP435E as those two have the 6.68:1 first gear (great for crawling) and those who tow love them because each gear is a little taller making it easier to haul a load.

THey were used behind SB and BB alike and I know that with a simple rebuild and mainanance kept up, they can handle a well build BB all day long.

 

Thanks for the trans info. If that's how the shifter is set up on all NP435 trannies, I have something different. Instead of having a long shifter mounted way up on the firewall, my truck has a much shorter one mounted nearer the seat, on a sort of hump that comes off the trans tunnel. Again, I haven't crawled under the truck to check the numbers on it or anything.

 

Soooooo ... After some poking around it looks like what's in there is an 833 four speed. Any chance that the 833 that sat behind a 225 will bolt to a Magnum with a new bellhousing? Will that tranny work with a 318 (LA or Magnum) at all?

It may be worth mentioning that I keep going back to the LA cause I found one that is complete from air cleaner to starter on CL for $450. Allegedly runs and has 98k miles ...

 

In the interest of full disclosure, I haven't do this swap, so take my info for what its worth....

I believe you can use the A-833 4 speed tranny with a small block bell housing but if not mistaken the truck version has a huge pinion bearing. Measure the bell housing you have at the opening. And compare to the new one. Any decent machine shop can cut a new pilot hole for you if you need it. I have heard you can swap the bearing to the smaller one but I haven't done it. That may be easy way to go.

 

It could very well have a 833 tranny behind it. I'm not sure what Dodge used behind the slant 6 in the trucks. If you can take a picture of it, I can help ID it.

Is it still in the vehicle so that you can here it run and maybe drive it? If not, I would still take it apart and inspect it.

 

Thanks again for all the helpful information fellas. This is great.