From slant 6 to wich small block?

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valiant_1969

Mopar
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hey,
i am about to swap my slant 6 to a v8, i'm taking information to left and right but i still don't have my idea done. i want a small block for sure, I want some horsepower but here in quebec de price of gas is a bit expensive, so i was thinking about a 318. i want around 300hp, i want to know if it's easy to get that with a 318, and if it would be a lot more expensive than having a 360 with that amount of horsepower. thank you
 
Ethier engine will make 300hp very easy. IMO, I would get a 360 because it would do a few things for you over a 318.

1st, it will make more torque.
2nd, require less cam to make the power sought
3rd should be, rebuilding it, pistons cost less, everything else the same.

The 360's came stock for the most part with 250+ HP with a broom stick for a cam. The 340 made 275 and with the addition of headers, 300 HP. Equip your 360 with a 340 cam and add headers.

Mileage can be fine with a 360. Alot depends on rear gear ratio and state of tune. The best mileage will be obtained with a Hwy. gear like a 2.76 or 2.94. You'll not be a rocket off the line though. I would add a MSD box to a vacuum advance distributor (Factory unit is fine) for best mileage results.
For an intake, the iron 4bbl will do just fine as well as the factory 4bbl carb. If ethier or not in hand, look for a Edelbrock RPM and a 650 cfm Edelbrock thunder carb. It is an AVS style carb with tuneable secondary door.
The only header worth installing IMO, would be Doug's or tti's, which cost alot of money, but OH so worth it.
 
I agree.

I'd like to make mention that in my old '79 Magnum with a all stock low compresion 360, I was able to get 20 MPG's out of it in a 3700+ LBS car. The rear ratio was a 2.76 and tires were 26 inch.

No cam change ethier. No headers, dual exhaust and good power. NOT 300 HP though. But the car moved well for it's heavy self.
 
Just for grins and jiggles. Check the differences of the gross and net HP and torque numbers on stock 71 318 and 360s.


71_Monaco_Polara0012.jpg
 
thank you, the only reason why i wasn't sure for the 360 was because i was almost sure it would cost a lot more fuel for almost the same power =/. as i can understand, the difference is not that big?
 
Keep your foot outta the secondaries and you'll never cry foul. LOL!
 
360 with a Thermoquad is the way to go.
Very small primaries and the bigger displacement means really good torque,throttle response and fuel mixing during normal driving.
Huge secondaries only feed as much air as the engine can take and also gives you that splendid 4 bbl moan.
 
yes i was thinking seriously about the thermoquad, ill probably go for a 360 :) im looking to get one now ;) thanks again
 
Use a new style 360 (5.9L) Magnum out of a van or truck. Quick burn heads, high compression, roller cam. Just change the intake and you'll love the mileage and performance. It also comes with a flex plate that is externally balanced already. The older ones have the long cam for the fuel pump eccentric and use the old style components on the engine. (timing cover,360 pan etc) The newer Magnums will require either a long cam nose or a electric fuel pump.
 
Huges has a bolt on fuel pump ecentric for the Magnum engines. The electric fuel pump aint a bad idea, but a pain IMO. Catch 22, take the front of the engine off or plumb a fuel line.....
 
What years are we talking here. Pulled 71 340 out of 68 gts ,tearing it down today to see how bad it's hurt. Mighht have to start over, get more bang for the buck with 360 but what are the pitfalls.
 
newby said:
What years are we talking here. Pulled 71 340 out of 68 gts ,tearing it down today to see how bad it's hurt. Mighht have to start over, get more bang for the buck with 360 but what are the pitfalls.
Click to expand...

Get the engine complete? None.
 
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