What should my 360 run

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Moparhead

Moparhead

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I just picked up a 360. That’s going into a 68 barracuda. It’s pretty close in combo to my 340. But it’s a 72 360 30 over forged pistons 10 to 1 comp 484 purple ofb rpm heads rpm intake 750 carb. My 340 made 420 hp with same cam 10.5 to one comp and x heads so I’m confident it will be close but any guesses on 1/4 mile 391 gears and 4 speed
 
Moparhead said:
I just picked up a 360. That’s going into a 68 barracuda. It’s pretty close in combo to my 340. But it’s a 72 360 30 over forged pistons 10 to 1 comp 484 purple ofb rpm heads rpm intake 750 carb. My 340 made 420 hp with same cam 10.5 to one comp and x heads so I’m confident it will be close but any guesses on 1/4 mile 391 gears and 4 speed
Click to expand...
I honestly feal my Xs are flowing better than the rpms.
 
with traction mid 11's ???? IDK... really hard to say
 
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The stick is always a wild card.

Take 420hp..... STP power from an engine dyno, and assuming it’s a street car.
Knock 10% off for corrections.
Take another 5% off for in car parasitic losses...... puts you at 360hp as it sits in the car........ assuming you’re not racing at an altitude factored track.

360hp@3500lbs...... should go about 110.

110mph could be a high 11...... but I’m thinking an 833 with not enough low gear, plus not enough rear gear, and probably not a “full on” launch....... more like a mid-12....... at a non-altitude adjusted track.

For comparison......
My 340 made STP 454hp the way it came out of my car.
68 B body, weighing about 3500lbs...... 5.13’s, slicks, 48-4900 stall.... went a best of 11.66@117.
60’s were soft....... not enough stall or gear.
“Shows” 432hp on the Moroso calculator.

So, sure..... 11’s are possible. It’ll really depend at least as much on the car as the motor.
 
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Moparhead said:
I just picked up a 360. That’s going into a 68 barracuda. It’s pretty close in combo to my 340. But it’s a 72 360 30 over forged pistons 10 to 1 comp 484 purple ofb rpm heads rpm intake 750 carb. My 340 made 420 hp with same cam 10.5 to one comp and x heads so I’m confident it will be close but any guesses on 1/4 mile 391 gears and 4 speed
Click to expand...
what did the 340 run ?
 
The 340 is the quicker motor. Something about that thing has 10.5 to one comp dome pistons. Pulls for days and hoocks up on the bfg radials.low 12s to mid 12s.
 
Had a buddy with a 340 only difference had a 508 cam and m1. And 2500 stall 355 gears ran 12.70 in a 71 dart. Suposto be 425 hp but im sure that was on street tires as well.
 
first day out; 106, meh 104; maybe 102.
Why?
Cuz nothing will go right.
The shifter will stick, the tires won't hook, you'll miss third,,twice, you won't find the trap,she'll run hot, the tiiming won't be right, the carb is fat, yada-yada-yada. You'll only get three runs in before lunch, and yur so PO'd you'll want to call it a day............
Oh wait.......
that was my first day,lol.
Fourth run was a charm; 93 in the Eighth. Time for some commemorative event T-shirts and track food. Booyah
 
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PRH said:
The stick is always a wild card.

Take 420hp..... STP power from an engine dyno, and assuming it’s a street car.
Knock 10% off for corrections.
Take another 5% off for in car parasitic losses...... puts you at 360hp as it sits in the car........ assuming you’re not racing at an altitude factored track.

360hp@3500lbs...... should go about 110.

110mph could be a high 11...... but I’m thinking an 833 with not enough low gear, plus not enough rear gear, and probably not a “full on” launch....... more like a mid-12....... at a non-altitude adjusted track.

For comparison......
My 340 made STP 454hp the way it came out of my car.
68 B body, weighing about 3500lbs...... 5.13’s, slicks, 48-4900 stall.... went a best of 11.66@117.
60’s were soft....... not enough stall or gear.
“Shows” 432hp on the Moroso calculator.

So, sure..... 11’s are possible. It’ll really depend at least as much on the car as the motor.
Click to expand...
I have the 309 first gear in my 4 speed.
 
AJ/FormS said:
first day out; 106, meh 104; maybe 102.
Why?
Cuz nothing will go right.
The shifter will stick, the tires won't hook, you'll miss third,,twice, you won't find the trap,she'll run hot, the tiiming won't be right, the carb is fat, yada-yada-yada. You'll only get three runs in before lunch, and yur so PO'd you'll want to call it a day............
Oh wait.......
that was my first day,lol.
Fourth run was a charm; 93 in the Eighth. Time for some commemorative event T-shirts and track food. Booyah
Click to expand...
My 340 launches hard on the street I feal like all this 100 percent accurate. Never liked running on the strip for too long **** starts to break lol.
 
Moparhead said:
The x heads have had the ports cleaned. They will be as good.
Click to expand...
I don't see the 360 giving up anything to the 340. I would "guess" the 360 would net you a better time. You might have to shift 200 rpms sooner with the 360 using the same cam as the 340, but from my experience, the 360 should run a little better
 
Moparhead said:
What et?
Click to expand...
no way to know,
but the DC Bulletin Book says that at
3500 pounds , 106 would be 3500/10.4= 364hp.
And that is predicted to go 12.5 with SuperStock suspension.
With street suspension and wrong gears, etc, figure another .6 to 1.0, so 13.1 to 13.5? Most of that will be on the launch, when the tires let go.

BTW, I got that Commando box too, with it's 3.09low. But I only run 3.55s now. I really really like it.

Moparhead said:
Never liked running on the strip for too long **** starts to break lol.
Click to expand...
I got 4 runs in; only one completed. Nothing broke so called it done.
 
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Ran 12.9 with a really basic 340 484 rpm intake 750. No bottom end work at all stock j heads. 3500 stall 391s. This one is a lot more built and a lot more quicker.
 
at my elevation and average DA during the summer, mid to high 13's
 
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