Bang for your buck. 5.9 magnum in a street car or pickup

[HankRearden]

I'll be working on multiple 5.9's for the next year or two for a few projects. I've been trying to weigh how best to allocate funds.
I've kind of been of the thought that a stroker with stock cylinder heads is a waste. But the previously posted you tube video did amazing torque numbers with stock heads and cam. It's kind of making my question my thought process.

What say the experts? And the know it all trolls?

For reference here is the stroker kit I've been eyeballing.

CHRYSLER 360-408 BAL. SCAT STROKER KIT Hypereutectic(Dish)Pist., I-Beam Rods | eBay

 

[goldduster318]

If you have the stock heads and they aren't cracked, you already are going to have to buy springs and retainers to run a good cam. So I would go with the aftermarket heads.

 

[Topless69]

I watched the video and was surprised with the Dyno results. If you’re want max bang for your buck the scat kit looks good although you may not want dished pistons. Even with mildly ported stock heads and a somewhat bigger cam 400+hp and 500+tq should be within reach. It sure would be interesting to see you build your 5.9 with the exact same parts and Dyno it to see if you get the same numbers. I really wanted to see them run it up to 5500+rpm.

 

[Darter6]

When Mopar was selling the 380 hp Magnums my neighbor put one in his 72 Duster.5.9's are stout engines.
The car runs high 12's full street car. That's with Iron heads. But if I had the money and the engine was going to need rebuilt I would do both. Stroker kit and Aluminum heads.

 

[Plymouth 65]

Do the SCAT stroker kit and work your stock heads. Determine what your CR would be, might be a bit low with dished pistons. I'd shoot for 10:1 and a decent cam to use it. 3500 stall converter and 3:91 Sure Grip rear. 65'

 

[rumblefish360]

@HankRearden What is the goal of the car?

Perhaps this thought will help.

Stroker kit = Torque now
VS
Cylinder heads = HP later

 

[PRH]

What are the chances the original heads aren’t cracked and/or have fairly substantial exhaust seat recession?

 

[TT5.9mag]

It’s a weekend job to swap cylinder heads, so depending on the goal for each individual car and the condition of your current heads, the stroker kit should come before the cylinder heads and that would allow for future improvements. Just know that a stock magnum head on 400+ inches is like drinking a thick milkshake through a straw.

 

[Topless69]

It’s a weekend job to swap cylinder heads, so depending on the goal for each individual car and the condition of your current heads, the stroker kit should come before the cylinder heads and that would allow for future improvements. Just know that a stock magnum head on 400+ inches is like drinking a thick milkshake through a straw.

I love milkshakes!

 

[HankRearden]

@HankRearden What is the goal of the car?

Perhaps this thought will help.

Stroker kit = Torque now
VS
Cylinder heads = HP later

So the way I'm looking at this as long as it is for street torque is the priority. The camshaft could be tailored more to the weight,gear ratio etc. I may be wrong though. I've never actually owned anything over about 350 hp. maybe hp is better for street.
But the torque of the 440 in my 74 dart was a lot of fun for doing donuts on dry pavement.

In my case I'm currently building a 5.9 for a 79 d200. The next will be for 79 cj7, then the 79 plymouth arrow pickup and probably last will be the 70 dart.
I can't throw a rock without hitting a rotted out ram with a 5.9 so they are going in everything.

It seems the only aftermarket heads available for the magnum are Edelbrock and trickflow now and neither are what I consider a budget option But I never expected the torque numbers mentioned in the video so I never considered a stroker knowing cylinder heads weren't in the budget. Just a home port job.

Its an intriguing thought anyway.

 

[Topless69]

Just spitballin’ here but looking at your four upcoming stroker builds you could use a different cam on every one, or keep it simple and shoot for torque on 2 and HP on 2 - dealers choice. You could also save a chunk of money on the CJ7 and Arrow PU by just doing a solid rebuild with an aftermarket intake, carb, cam and headers... Arrows & Jeep’s are so light they don’t need tons of power.

 

[HankRearden]

Just spitballin’ here but looking at your four upcoming stroker builds you could use a different cam on every one, or keep it simple and shoot for torque on 2 and HP on 2 - dealers choice. You could also save a chunk of money on the CJ7 and Arrow PU by just doing a solid rebuild with an aftermarket intake, carb, cam and headers... Arrows & Jeep’s are so light they don’t need tons of power.

Oh 4 strokers arent in the budget but the d200 might be the perfect candidate for one. The arrow is going to be a daily driver so like you said stock rebuild with a cam is probably the way to go. The dart and CJ who knows. Sure is nice tha 5.9's are so cheap though.

 

[Topless69]

Oh 4 strokers arent in the budget but the d200 might be the perfect candidate for one. The arrow is going to be a daily driver so like you said stock rebuild with a cam is probably the way to go. The dart and CJ who knows. Sure is nice tha 5.9's are so cheap though.

Got that right - d200 with 375 & 500ft lbs. will be an awesome rig. I’d love to be cruisin’ around in a Dart or Jeep with that kind of grunt too. Imagine the fun!

 

[rumblefish360]

It seems the only aftermarket heads available for the magnum are Edelbrock and trickflow now and neither are what I consider a budget option But I never expected the torque numbers mentioned in the video so I never considered a stroker knowing cylinder heads weren't in the budget. Just a home port job.

Its an intriguing thought anyway.

You can use an LA head on the Magnum but you’ll need to oil the rockers with hollow pushrods and the proper lifter which is normally supplied with the camshaft.

The rockers that allow oiling are ether Comp Pro Magnums (1.5 ratio only) or the PRW rockers which are available in a 1.5 or 1.6 ratio.

 

[TT5.9mag]

I love milkshakes!

Who doesn’t?

 

[273]

Depends what type of performance guy you are.

One camp builds for hp and goes with the gears and stall for best performance, for this heads all the way.

Second wants compromises, like will only run a particular gear and or rpm range where the bigger the engine will definitely have the advantage.

Say you want power from idle - 5000 rpm, which would be about 350 hp with a 360 and stock heads have more than enough flow to accomplish this goal. The only real way to increase hp in this powerband more displacement as long as the heads can support it, the stock head could with 408 making peak at 5000 rpm too.

 

[Bewy]

Putting 360 heads on a 400 engine....will make about the same HP, just at a lower rpm. The 'bigger' heads thing is overdone. If the 360 head ports are oversize for the job, they would work well on a larger engine.
Pontiac used the same heads, same valve & port sizes, on engines from 350 to 455.

 

[273]

Putting 360 heads on a 400 engine....will make about the same HP, just at a lower rpm. The 'bigger' heads thing is overdone. If the 360 head ports are oversize for the job, they would work well on a larger engine.
Pontiac used the same heads, same valve & port sizes, on engines from 350 to 455.

True, but there still some power left in the heads so a 408 can use more cam to peak at 5000 rpm like 360, should make more hp from idle-5000 rpm compared to the 360 at the same powerband.

 

[Bewy]

273.
Well aware of that. My point was that 360 heads are not necessarily bad depending on what the end goal is.