Brainstorming Ideas for 400-450 hp 360 Build

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cawcislo

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Hello,

Here's what I'm trying to achieve before we get to the engine. Vehicle is a 70 Duster, 4 speed and I want to keeping it a manual. Looking to have a fun car that I will drive around the street during the 6 or so months that the weather permits (but it won't be my daily driver). Will also do some drag racing a couple times a year and possibly some auto cross. So it will get hammered on.

I have a 360 motor out of a 1980 truck I got for next to nothing as the duster currently has a 318 and I want to stay with a small block. What should I be putting my money towards and how much should I budget? I'm looking for the motor to last and I would like to run pump gas (91 octane premium is fine). Let the games begin....
 
Step one...... come up with a budget.
For everthing associated with the motor.
IGN, carb, headers, cooling, etc.

Deduct those essentials from the budget, what you have left is for the long block........ and how much that is will usually dictate how the build will go.

It’s not hard at all to make over 400hp from a pump gas 360.

That being said, “if” the proposed build includes forged pistons and aftermarket rods...... you’re only the price of a stroker crank away from a 408.
 
Can you spend $2000 on cylinder heads? That's where you want to put your money.

Do you know the condition of the 360 you got? If the cylinder bores are in good shape you could just keep the stock bottom end and put heads, cam, intake etc although the compression will be limited by the factory pistons. If not you'll need an overbore, hone, perhaps a square-decking if you want to build an engine with quench (it's nice but not needed). Either recondition/resize factory rods with new bolts or get aftermarket rods, or leave them alone if you aren't going over 450-ish HP.

I built a 425-ish HP (would be closer to 450 if I swapped the 1 5/8" shorty headers for proper long-tubes) 360 using a bone-stock 5.9L Magnum short block from the junkyard out of a 2000 Ram 2500, didn't replace anything except the rod bearings. Bolted on a pair of ported Edelbrock aluminum heads with Cometic head gaskets and head studs (9:1 compression, she's waiting for some boost!!), got a custom-grind hydraulic roller cam from Racer Brown, port-matched Performer RPM intake manifold, Hedman shorty headers.

Haven't had it down the 1/4-mile or run on a chassis dyno yet but my previous 360 made around 330 HP and this one pulls WAYY harder past 3500 RPM all the way to 6000. Still has excellent torque and drivability below that RPM as well, pretty much right off idle. Custom-grind cam FTW!
 
I second the suggestion to set a budget. I didn't and it spiraled out of control chasing a number.

I started with a 1978 360 out of a van

Bought a SCAT stroker kit with forged I beams, Forged Icon Pistons and crank. I had the machine work done and the blocked decked as well.
I ordered a cam from Bullet and they custom ground one to my specifications, hydraulic flat cam. Cam specs CRA288/296H-08+4, @.50 231/239, .485/.503 Lift with 1.5 rockers, 108/104 LSA/CL.
I had stock iron heads off a 1973 360 with small valves, smogger heads.
I had a Chinese Airgap dual plain intake with a new Quick Fuel 750VS with electric choke.
I ran a stock electronic ignition and Dougs A body long tube headers.

This combo made 427HP and 460 torque on an engine dyno. Great numbers and very solid.

I should have stopped there but has since gone with a Lunati solid flat cam that has been custom ground for my application. I am running a ported Victor 340, CNC220 aluminum big valve heads and have upgraded to a TSP ready to run distributor. The new combo will go back in the car this week and will get run on a chassis dyno to tune as I am having a custom billet carb built for it by Thumper Carbs.

The first version of the build, I had about $4200 including machine work and parts. I assembled it myself.

As stated, it is not difficult to have a 400hp pump gas 360, its very easy to have a 427hp and 460 torque 408.
 
I second the suggestion to set a budget. I didn't and it spiraled out of control chasing a number.

I started with a 1978 360 out of a van

Bought a SCAT stroker kit with forged I beams, Forged Icon Pistons and crank. I had the machine work done and the blocked decked as well.
I ordered a cam from Bullet and they custom ground one to my specifications, hydraulic flat cam. Cam specs CRA288/296H-08+4, @.50 231/239, .485/.503 Lift with 1.5 rockers, 108/104 LSA/CL.
I had stock iron heads off a 1973 360 with small valves, smogger heads.
I had a Chinese Airgap dual plain intake with a new Quick Fuel 750VS with electric choke.
I ran a stock electronic ignition and Dougs A body long tube headers.

This combo made 427HP and 460 torque on an engine dyno. Great numbers and very solid.

I should have stopped there but has since gone with a Lunati solid flat cam that has been custom ground for my application. I am running a ported Victor 340, CNC220 aluminum big valve heads and have upgraded to a TSP ready to run distributor. The new combo will go back in the car this week and will get run on a chassis dyno to tune as I am having a custom billet carb built for it by Thumper Carbs.

The first version of the build, I had about $4200 including machine work and parts. I assembled it myself.

As stated, it is not difficult to have a 400hp pump gas 360, its very easy to have a 427hp and 460 torque 408.

I should add that those numbers were at 5500 rpm for HP and 4600 for torque
 
Put good heads on it and it'll be easy.
 
Make it breathe and it's easy to get a 360 over 400HP with not much camshaft.
 
360 stock crank
10.5 comp
ProMax, TrickFlow, or ported Edelbrock heads
.520 racer Brown solid lifter cam
gasket matched Victor340 or LD340 intake
750 Holley
shift at 6400-6700 and it should last a long long time.
 
. Looking to have a fun car that I will drive around the street during the 6 or so months that the weather permits (but it won't be my daily driver). Will also do some drag racing a couple times a year and possibly some auto cross. So it will get hammered on.
There's the rub;
As a streeter you need to decide right now how much gear you can run. Because this decision, with a manual trans, will pretty much dictate your cam selection, which will dictate at about what rpm the power will peak, and that will to a large extent dictate the power number. Now if that ain't enough, then it's back to the drawing board. If the engine is already built, with an optimized Scr for a particular camshaft, then it gets expensive to redo. Far cheaper it is to then just change the rear gear, and suffer the consequences.
What I mean to say is this; I ran a 292/292/108 Mopar cam in my 367 equipped 68 Barracuda with a regular 2.66low 4 speed and 3.55s. That beast made lots and lots of power beginning at 5000... which was 42mph, and pulled hard to 7000@60mph. All in first gear. Ok but the power didn't begin until ~40mph...... in first gear. So cruising along at 30 mph in second was 2600rpm, and if you have an 8/1 compression engine,the horses are in the barn at that rpm. So if you need to move out, you are forced to downshift, hit 3600, and wait for the power to hit....... and wait and wait, until 40mph. Yeah so that would suck.
But I had 11.3scr/aluminum heads, and it still kindof sucked.
But, with iron heads you pretty much need that [email protected] cam to hit your numbers.
But, now if that 292cam ends up a PITA for you, as it did me, then if your cylinder pressure was optimized to run it, then you may not be able to run a smaller camshaft, because the pressure may put your iron-headed monster straight into detonation.
Ok so that was with 3.55s and a 2.66low 4-gear.
But that optimized combo wants 4.30s with that 2.66low, so that the 5000 rpm power hit comes at 34mph in first gear, now yer cooking!
Or if you run a 3.09low Commando box, then you can run 3.73s for 5000=also 34mph. But when you hit second gear with this box, your engine better have some grunt......
The problem, if you can call it that, is the high-rpm power peak.

Better it will be to put some money into good heads and run a smaller cam, and make more power in the midrange, to still make the power you crave. This makes a fun streeter. Then at the track, just let it be what it will be. With a street suspension, you are gonna be about a second slow anyway for your trapspeed, so either grin and bear it, or build a dedicated track car.

I ended up with an optimized combo with a 230*cam, that is a sweetheart of a street combo with 3.55s and a Commando box. I don't have to wait for the power-hit, cuz it spins 295s from off-idle in first, to initiating a spin at 50/55 mph in second gear, so she's always ready to blast. That's my kindof fun. How much power? IDK. and I don't care. For me, it's all about the fun-factor.
That's my 2cents worth.
 
There's the rub;
As a streeter you need to decide right now how much gear you can run. Because this decision, with a manual trans, will pretty much dictate your cam selection, which will dictate at about what rpm the power will peak, and that will to a large extent dictate the power number.

That about sums it up.

With true street cars, most of the time it comes down to how much gear and/or stall the owner can tolerate, and to some degree whether or not it has power brakes....... which will(or at least “should”) dictate the direction of the build and how big the cam can be.

Obviously, the milder the desired combo is, the more benefits you’ll get in the “seat of the pants” driving experience with additional cubes.
 
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360 stock crank
10.5 comp
ProMax, TrickFlow, or ported Edelbrock heads
.520 racer Brown solid lifter cam
gasket matched Victor340 or LD340 intake
750 Holley
shift at 6400-6700 and it should last a long long time.
And run like a scalded dog! :rofl:
 
re read aj's comments till you understand them and the tradeoffs
Which is why I asked "at what rpm"
do we know what gears in trans and diff at this point"
if not a dedicated race car then big wide torque curve
can't beat cubic inches
good heads for broad torque curve
nothing worse than too big heads and too big cam when you're shifting around town more often than Saturday night
 
Stroke to 408. easy 450 hp with trick flow head or edlebrock and much milder cam than a 360.
No matter what head you use on the 360, it's gonna take a radical cam to achieve 425 hp the midrange of your goal.
A 450 hp 360 will not have good street manors.
Spend your money wisely once. build a 408.
 
Stroke to 408. easy 450 hp with trick flow head or edlebrock and much milder cam than a 360.
No matter what head you use on the 360, it's gonna take a radical cam to achieve 425 hp the midrange of your goal.
A 450 hp 360 will not have good street manors.
Spend your money wisely once. build a 408.
I would agree with this comment, however I made nearly 430hp with small valve, iron "J" heads and a relatively mild hydraulic cam. If I had gone a bit more aggressive versus conservative on my cam choice, it would have made a better number. There was allot left on the table but still a very respectable, reliable daily driver number.

Heads is absolutely the key in these engines but my example shows you can make well over 400hp on a budget.
 
I would agree with this comment, however I made nearly 430hp with small valve, iron "J" heads and a relatively mild hydraulic cam. If I had gone a bit more aggressive versus conservative on my cam choice, it would have made a better number. There was allot left on the table but still a very respectable, reliable daily driver number.

Heads is absolutely the key in these engines but my example shows you can make well over 400hp on a budget.
your 408 with iron heads IS respectable at 430 hp. But it is under headed for any future big hp gains.
If I'm building an engine and need to sink money into refurbishing heads, I'm moving to aluminum for a few more bucks.
 
You can make 425 hp pretty easy
360 .030 over 9.5/7.9 static/dynamic
.528 solid purple cam installed 4 degrees advance
mildly ported 2.02 heads x or j etc...basic iron that do the old 245cfm by .500 -very basic average etc..
rpm intake
750 carb
cheap headers or good ones.... does'nt matter.
It doesnt take much. 360 is a great motor.
 
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