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Building a 360 magnum for a '94 Dodge Ram 1500

Posted By: Highwaystar94

Building a 360 magnum for a '94 Dodge Ram 1500 - 03/21/17 06:29 AM

I'm planning on building a 360 magnum for my '94 ram 1500 and i was curious if you had any advice on the build for me. I want a build that keeps the torque curve low enough that I can still use my truck as a truck (mainly hauling motorcycles) But i would like it to be in the 400hp range I plan to swap out the 4 speed 727 for the T-56 (the 6 speed used in challengers) I know that the Cam in them is incredibly tame so upgrading that is likely, However this will require either to chip my current computer or buy a new one there? advice appreciated. Also i will replace the heads as I've found out the stock magnum heads are almost always cracked. My truck right now has the 318 magnum in it but i plan to pull a junkyard 360 because there is no replacement for displacement and the 360 will bolt right in. Finally I'm looking to keep costs as low as possible because I'm 17 and cash isn't easy to come by.
Posted By: Andrewh

Re: Building a 360 magnum for a '94 Dodge Ram 1500 - 03/21/17 03:08 PM

So I see a couple of problems with your keeping costs down.

that manual swap will mean a new engine computer, as the automatic is different than the manual.

adding the 3rd pedal? not sure how bad that is for a modern truck, other than sourcing.

and then the actual t56.

for the junkyard 5.9, be aware that you might need to reuse all your sensors and injectors if you plan on using your existing harness.
98 and up the connectors changed.

someone else will have to come back with how to get a 5.9 into the 400hp range and still keep the stock computer.
Posted By: MarkZ

Re: Building a 360 magnum for a '94 Dodge Ram 1500 - 03/21/17 03:36 PM

If money is that tight then I would divide and conquer - do either the motor or the transmission first, but not at the same time. The 518 you have in your truck has an electronically controlled 4th gear (all it is 12v applied to a solenoid). It won't present any issues.

The cracking in Magnum heads typically isn't anything to worry about either. When you pull the 318 out take the heads off and have a look. If they're in better shape then go ahead and bolt them onto the 360 as they're the same heads.

I can't speak to the computer, but if it were me I would slide the 360 in with a pair of long tube headers and an M1 intake and re-evaluate from there. If budget allows then 4" cast stroker cranks are only $300. A 408 Magnum motor utilizing stock heads would make for a good truck motor.
Posted By: HotRodDave

Re: Building a 360 magnum for a '94 Dodge Ram 1500 - 03/21/17 06:44 PM

Didn't the viper truck get a zero towing capacity rating when equipped with that trans because it can't handle the constant heavy load?

If I was on a budget I would just take the stock 5.9 mag completly apart, square the deck and mil it about .030 to get near zero deck (measure to be sure but this is what I typically find gets me within .005), then run a MrGasket thin head gasket to get nice tight quench and more compression, this make more power MPG and makes it very knock resistant. Do a basic 3 angle valve job, ignore the cracks they are there but don't seem to ever hurt anything. If your budget allows get the cam re-ground by deta cams if not then use the 318 cam, it is slightly better cam than the 5.9 comes with and the 5.9 cam is bigger than the 300HP crate motor cam so it ain't too bad when talking free cams. If you can afford the re-grind (around $100 with shipping) tell em you want as much lift as possible and no more than 205 duration at .050 single pattern and 110LSA. If you really want 400 hp you will need a better intake, the hughes airgap is good for that and readily available but you lose some valuable TQ down low in a heavy truck. There is no way around it as the very long runners in the stock intake make a lot of TQ down low but you have to shorten them up to get HP, the airgap keeps the air much colder going in the engine and that helps some but when towing there is still a significant loss of usefull TQ.

The 408 strokers work awesome for trucks but DO NOT GET THE EAGLE CAST CRANK! I have personally seen a few of them break in very mild aplications, get the SCAT crank and external balance it, internal is better but you might as well cough up for forged at that point because you will need expensive mallory metal to internally balance the cast one and it will cost as much as the forged one and not be as good. Also if you go stroker you will want to shlep on down to your favorite junk yard and pull a set of fuel injectors off a 460 ford engine. The 408 can be very rewarding but tends to sno-ball in cost.

If you have to bore your block but stil want to be a little cheaper than the stroker then a set of KB107s help reduce cost by eliminating block milling then you can use that money to balance it witch helps if you are turing up the RPM.

Another trick I found that helps and is free (if you do it yourself) is to reduce the PR pinch, even grinding out about .050 on the PR bump will improve the injectors shot at the back of the vave instead of just squirting fuel into the side of the port. No matter what you settle on for a plan this helps a magnum motor.

If you are on a really tight budget you coud buy the 5.9, put in the 5.2 cam, pull the heads and buy one MrGasketMLS head gasket, take it apart and use the thin outer layers for individual head gaskets, this will get you almost good quench and a little more compression. Make sure you block and heads are both very clean and smooth before doing this and I spray both sides of the gasket with copper coat if the block and heads are not freshly resurfaced. This motor will pull quite a bit harder than the old 5.2.
Posted By: jerseybud

Re: Building a 360 magnum for a '94 Dodge Ram 1500 - 03/22/17 01:45 AM

You MUST use a 5.9 computer if running a 5.9. The 5.2 will run the 5.9 albeit lean. Going from an automatic to a manual, you do not need to change the computer in trucks 95 and earlier. Need a new comp if vice versa (manual to auto). Comps must be from 94-95 models only

If budget is an issue, just buying the t-56 will blow it, let alone the clutch hydraulics. The NV4500 is the superior tranny is a towing truck- its behind the diesels albeit in a beefed version. You need the gas version- theres about a million little stupid parts for a swap like this so I hope there are some junkyards near you b/c getting it on ebay will be $$$$. Parts truck is always a good idea

400 hp will require a pretty stout cam. Roller cams ain't cheap. Hughes has some good ones though that may get you near it and keep respectable low end torque. 360 hp at the flywheel more realistic for a towing engine.

The RHS/engine quest heads from Hughes are a good way to avoid machine work costs and get the thicker decks. They flow slightly better than stock as well so that helps your power wish. Still not cheap

I've just spent alot of money
550 for 5.9 JY engine with mid level miles
1000 for nv4500 in good shape
200 for nv4500 bell
100 for hydraulics and pedals if you're lucky
350 for cam
1200 for heads
140 for 5.9 flywheel
150 for clutch kit
$$$ aside for driveshaft work possibly (shorter or longer?)
60 new crank sensor for manual tranny
60 special fluid for nv4500
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