68 coronet 318 or 360?

[LEND]

Hey guys! I just got my first mopar a 68 coronet it came with a 318 from the factory and has a 318 now. I want to have a nice street ride with some decent hp of 350-450 hp Im not gonna race or anything but i would like her to put me back in my seat when you hit the gas. I talked to some guys and some say stick with the 318 and the 906(i think that's the number) transmission and some say 360 and 727. I'm not a mopar guy so what do the diehard mopar guys think? if you walked up to my car and it looked awsome on the outside what would you like to see in powertrain original set up beefed up or 360? Thanks for the help

 

[prplcar]

Go with what fits your budget, a 318 and 360 for the most part look the same. Don't put displacement tags and it can be what people want to think it is. Both tans are good, I use a 727 behind my big block.

 

[Cranky]

A well built 904 will handle the power of the 360 and the 904 robs a bit less horsepower just because the internal parts are a bit smaller in diameter....but you will have to use an external balance flex plate for the 360 since it's balanced that way and the teen is internal balanced.

 

[LEND]

Thanks- I am kinda leaning towards the 318 and the 904. i did some reading and it looks like you can get some pretty good HP out of the 318.

 

[rumblefish360]

I've been down this road several times and I'll tell you there's no replacement for displacement. In order to save money and time, and I'll not waste your time, stay with a small block and make it a 360. Build it to the side and when your ready to drop it in, it'll be ready to go and with as little down time as possible. You will still be able to drive your car while you do the build up.

The basic budget build parts for a 360 are as followed;

KB 107's
Moly rings
Replace your con rods for a new set.
This works out cheaper than resizing your rods.
Cam duration to match your gears and driving RPM
RPM intake
650 carb, Holley or Edelbrock AVS, your choice.
You'll not need a bigger carb.
Bowl port your heads.
I seriously suggest Hooker Super Comp headers or TTI's
The fit is way well worth the price over the cheapy standard 1-5/8 headers that really suck to install and almost always get smashed due to there design.

You may want to deck the block to have a zero deck height. This with a .38 head gasket and a 72 cc head chamber will yeild 9.8-1 for a ratio. A thicker head gasket @ .055 will drop it to 9.5-1.

The stock heads offer a cheaper route than aluminum heads but less ceiling in performance. You'll not need much for your goal and the factory heads will do it.
The smallish carb has plenty of CFM for the power to be made. The best thing about it over a 750 is the amazing throttle response you'll get.

Use a split duration cam with as much lift as you can get. Something in the area of 230 @ .050 intake and 6-8 degrees more exhaust.

2-1/2 inch exhaust. Screw the 727. Use a B&M flex plate to match the different balances or have the 360 internally balanced. A better choice IMO.

Now go getter done! Enjoy!

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Oh, by the way, there is a huge differance between 350 & 450 HP.
Keep in mind the old MoPar create engines were a 9.0-1, used there purple 294/.484 cam, there single plane intake and STOCK heads with 2.02/1.60 valves to make 380HP. They also recomended a 750 carb and 1-3/4 headers.

There's no shame in a copy cat engine or a simple change to the copy cat engine for a better driver. Porting the heads is worth 40 if there done right. And if you go that route, use the 750 carb.