Stock 360 from a 1984 Dodge Pickup

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DusterDaddy

DusterDaddy

sledgehammer mechanic
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Hello All
I bought a good running 360 from a 84 pickup to put in my 74 duster project.
Got some advise from guys on this forum to just run the motor the way it is if I'm not willing to rebuild it right now.

I want to keep a stock look and i want to keep the stock intake on the motor, but eliminate all the smog stuff that would have been on that 84 truck. Can anyone help me with how to go about plugging ports on the intake I wont need?
I know I need to tap and plug the egr ports on the heads and I am clear on how to do it.

My 74 Duster is a factory 318 car with the stock exhaust manifolds. I know there must be a perfromance hit if I use the 318 iron exhaust manifolds on the 360 so I am looking for a drivers side 360 stock manifold. The passenger side exhaust manifold from the 84 truck looks like its the same as the 74 360 Abody manifold, is this a good plan to follow?

So when I get the motor in my 74 Duster with my beefed up 904 trans, I am planning to use a 650 cfm Holley on the stock intake with the smog holes plugged up nice and neat under a stock 360 snorkle air cleaner.

Any guess how that stock 84 truck motor is going to perform with the small Holley on it with stock exhaust manifolds and dual exhaust?

I would appreciate any feedback you all.....Thanks
 
Well I have a pair of '87 360 truck manifolds and your more than welcome to, at no cost. You have to come pick them up, but I am in Woodbridge, about 25 minutes from you.
 
Just..Make sure you have a oil pan that will fit...I dont know if truck 360 oil pans are different than cars..and get a nuetral balance flex plate, because a 360 is external balance and a 318 is internal.

It will run pretty good....given your carb is good, and close to spot on, and you can tune it.

.410" lift cam, 4.0" bore, 8.5:1 CR.....with 4 bbl carb, and free flowing dual exhaust, it will make approx. 320hp, and 350tq.....which will feel pretty nice for what this swap, costs to do.

Probably run a nice 14 sec. quarter.

Check out my 74 Duster 360 build:
http://www.forabodiesonly.com/mopar/showthread.php?t=91659
 
truck oil pan are rear sumps...car oil pans are center sumps...

the pan and pick up will need to be changed..
 
my opinion, get a factory 4-bbl 318 (1978 california) or 340 4-bbl manifold and slap it on there. You'll still have the factory look without having to plug any holes:)
 
The "holes" he is referring to have to plug, are the smog ports under the exhaust ports..present on every low-performance V8 cylinder head after 1974....You really need to weld/plug them...otherwise you'd have 8 exhaust leaks under each manifold/header.
 
The ports below the exhaust ports on the heads need to be sealed up. The easiest way is to tap them to 1/4x20, get some allen plugs and loctite them in. It's been done counless times over the years.

Bill S.
 
I was talking about the smog junk from the smogger ThermoQuad that is piped and tubed back to the intake manifold.
I have the smog ports on the heads drilled, tapped and plugged already.
 
1/4 20's worked great on my 360. easy and never had a problem. easy to do while out of the car.
 
Can you post a picture of the TQ?
For the most part, you can plug up all but one, the bowl vent on the side @ 3/8 hose size, should remain open.
Does this carb have a port for vacuum advance? If not, it is the wrong carb to use. However, if your Ok with drilling a hole for a vacuum tube for a vacuum advance....... Just copy an earlier version.
 
Ok
Here is the motor just after being pulled.
It was suggested in another post by members that if I don't have the funds to tear the whole motor down now, I should just run it as it is.
So the plan is to degrease and scrub it, do the oil pick-up and passenger oil pan, remove all smog components, plug the EGR ports on the heads and run it with a new small Holley or Eddy carb on the stock iron intake.
Everyone in the world says to ditch the 1984 era smogger ThermoQuad.
As you can see in the pics taken just after it was pulled from the truck there is a bout 50 miles of smog and air rubber tube on that motor.
The question is how do you run a stock 1984 360 with a stock intake with a non smog Holley or Eddy carb, and remove all the smog stuff?
 

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If your not going to tear into the engine, leave all the smog stuff on and hooked up. The engine will run better that way since it was designed to run that way. De-smogging the engine and leaving the smog carb on top will result in a poor running engine.

There is nothing wrong with the TQ? Then leave it.

IF you throw in a cam, select carefully and error on the small side. IF your going to use the exhaust manifolds, I recommend the comp cam line designed with this in mind. Click here for a look at such cams, the top 3 are the ones I'm thinking of, the middle one is what I would use in this build; http://www.compperformancegroupstor...en=CTGY&Store_Code=CC&Category_Code=LACAMHFDE

Gear ratio to be used is the biggest key here.
 
Thanks for the offer
I'm pretty sure the driver side manifold is very specific to A-bodies
is the driver side manifold outlet at the rear of the manifold
It is in the center on the 84 manifolds that are on the motor now
 
Prine
If I kept the motor from the truck bone stock from the manifold down, how do you think it would run with the right intake and carb.
If I did change the cam do i need to address the valve springs and rods too?
I heard that if I cap the ERG ports on the heads, that they will have decent flow, what do you think?
 
Prine said:
Just..Make sure you have a oil pan that will fit...I dont know if truck 360 oil pans are different than cars..and get a nuetral balance flex plate, because a 360 is external balance and a 318 is internal.
Click to expand...

Like 70aarcuda mentioned, you will need a 360 car oil pan which is basically a center sump like the 318. But the 318 pan won't work because the rear seal area is different.

As for flexplates, you will need a B&M 360 externally balanced flexplate because your 318 converter is neutral. (Make sure you DO NOT get the '93 & up B&M 360 Magnum flexplate because the external balance is difference.)
 
Been thinking it over and since I only have a few hours a week to get to the car, I'm leaning toward pulling off the heads and taking a look.
If I decide to do the cam, what should be done to the heads while they are off other than plugging the smog pump ports?
Im still hell bent on using the iron intake that's on that motor now too, just with a new carb.
What's better to do first the top of the motor then flip it to do the pickup and pan? Or do the bottom first?
 

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If you replace the cam, you have to replace the valve springs. If you do the springs, you have to remove the exh valve rotators. On my '87 in my truck, I removed all the smog stuff, tapped/plugged the holes, stuck a windage tray in it, replaced the cam with an XE262 Comp, a new timing set, a set of Comp 901-16 springs, and put back the 318 Performer and Edelbrock 750 that came on it. I also put an earlier distributor in it so it had the vacuum and centrifical advances, and put a performance curve in it, and an MSD 6AL. You could duplicate that for about $1500 with all new parts and never take the heads off. It's been running in my truck for 5 years. I changed the oil a couple times and rebuilt the carb once... That's been it for maintenance.
 
I would also suggest that if you pull the heads to take a look and a possible cam change. Take them to a machine shop if you are not too comfortable with changing the springs and have them do that and maybe a valve job. Do pick a mild cam designed for low compression and talk to different cam manufactures. From my personal experience it is better to under cam a motor than than over camming it.
 
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