'68 Dart with a 318 LA - Build Options

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KCBones

KCBones

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I've got a '68 Dart GT with the original 318, 904 auto, and a 7-1/4 rear end. I am getting ready to repair the front left frame rail and thought it would be a good time to freshen the engine and transmission.

First the engine. Like I said, its the original 318 but at some point during it's life had an Edelbrock Performer manifold and a Holley 4160 600 CFM carb put on it. It's also got some aftermarket plug wires so I don't know if anything has been done regarding the ignition system. My plan is to keep things as cheap as possible but I do want it to be a reliable fun car to drive. There's probably a million 318 Build threads here but I was just wondering from some of the experts here what might be an affordable plan. I was thinking about reusing the existing crank and rods, probably some sort of minimal overbore just to clean things up (assuming the machine shop says that's all I need to do), new pistons and rings, new bearings, upgrade the cam a little bit, and reuse the Edelbrock intake and the Holley. As for the heads, I'd like to find a set of old 302 swirl port heads if that's still possible and upgrade to an electronic ignition. I do have a set of old Headman A-body small block headers that some guy bought years ago and never installed, they were cheap so that fits in the plan.

As for the transmission, I was planning to stick with the 904, get a street rebuild kit from Cope Racing Transmissions, and maybe upgrade the torque converter if I can find one that works with a 904 trans without a real high stall. The floor shifter feels a bit sloppy so I'll need to do something about that.

For the rear end, I would love to find an 8-1/4 A-body unit that I could just bolt in, would really love it if it had a Sure Grip in it.

When I bought the car about a year ago, I had visions of a 340 4-speed swap with an 8-3/4 rear end. Pricing those parts brought me back to reality.

Any thoughts or suggestions on my new plan would be greatly appreciated.
Thanks.
K.C.
 
KCBones said:
I've got a '68 Dart GT with the original 318, 904 auto, and a 7-1/4 rear end. I am getting ready to repair the front left frame rail and thought it would be a good time to freshen the engine and transmission.

First the engine. Like I said, its the original 318 but at some point during it's life had an Edelbrock Performer manifold and a Holley 4160 600 CFM carb put on it. It's also got some aftermarket plug wires so I don't know if anything has been done regarding the ignition system. My plan is to keep things as cheap as possible but I do want it to be a reliable fun car to drive. There's probably a million 318 Build threads here but I was just wondering from some of the experts here what might be an affordable plan. I was thinking about reusing the existing crank and rods, probably some sort of minimal overbore just to clean things up (assuming the machine shop says that's all I need to do), new pistons and rings, new bearings, upgrade the cam a little bit, and reuse the Edelbrock intake and the Holley. As for the heads, I'd like to find a set of old 302 swirl port heads if that's still possible and upgrade to an electronic ignition. I do have a set of old Headman A-body small block headers that some guy bought years ago and never installed, they were cheap so that fits in the plan.

As for the transmission, I was planning to stick with the 904, get a street rebuild kit from Cope Racing Transmissions, and maybe upgrade the torque converter if I can find one that works with a 904 trans without a real high stall. The floor shifter feels a bit sloppy so I'll need to do something about that.

For the rear end, I would love to find an 8-1/4 A-body unit that I could just bolt in, would really love it if it had a Sure Grip in it.

When I bought the car about a year ago, I had visions of a 340 4-speed swap with an 8-3/4 rear end. Pricing those parts brought me back to reality.

Any thoughts or suggestions on my new plan would be greatly appreciated.
Thanks.
K.C.
Click to expand...
Sounds like you've got a good plan! A decent little cam (like the 340 stick cam) or something in that ball park will liven the little teen up quite a bit. 302 heads might be tough to find, but they're still out there and are a certain upgrade if yours are the old open chamber design. You could put a wanted ad for the heads and one for the rear diff and see if a member has any of those things.
 
cam bearings, cam, bore, rings, pistons, heads, gaskets.....Is it worth the work and money on a 318?
any used 360's kicken' around in your area
 
How does it run now?
 
ir3333 said:
cam bearings, cam, bore, rings, pistons, heads, gaskets.....Is it worth the work and money on a 318?
any used 360's kicken' around in your area
Click to expand...
I don't know. Seems like a lot of people build them. It's the original motor and I don't have to buy another core to rebuild. Seems like the pricey part would be the heads, I don't know what a good core set of these cost these days. If it ran reliably and had a little pep, I think it would be worth it but I'm just guessing.
 
KCBones said:
I've got a '68 Dart GT with the original 318, 904 auto, and a 7-1/4 rear end. I am getting ready to repair the front left frame rail and thought it would be a good time to freshen the engine and transmission.

First the engine. Like I said, its the original 318 but at some point during it's life had an Edelbrock Performer manifold and a Holley 4160 600 CFM carb put on it. It's also got some aftermarket plug wires so I don't know if anything has been done regarding the ignition system. My plan is to keep things as cheap as possible but I do want it to be a reliable fun car to drive. There's probably a million 318 Build threads here but I was just wondering from some of the experts here what might be an affordable plan. I was thinking about reusing the existing crank and rods, probably some sort of minimal overbore just to clean things up (assuming the machine shop says that's all I need to do), new pistons and rings, new bearings, upgrade the cam a little bit, and reuse the Edelbrock intake and the Holley. As for the heads, I'd like to find a set of old 302 swirl port heads if that's still possible and upgrade to an electronic ignition. I do have a set of old Headman A-body small block headers that some guy bought years ago and never installed, they were cheap so that fits in the plan.

As for the transmission, I was planning to stick with the 904, get a street rebuild kit from Cope Racing Transmissions, and maybe upgrade the torque converter if I can find one that works with a 904 trans without a real high stall. The floor shifter feels a bit sloppy so I'll need to do something about that.

For the rear end, I would love to find an 8-1/4 A-body unit that I could just bolt in, would really love it if it had a Sure Grip in it.

When I bought the car about a year ago, I had visions of a 340 4-speed swap with an 8-3/4 rear end. Pricing those parts brought me back to reality.

Any thoughts or suggestions on my new plan would be greatly appreciated.
Thanks.
K.C.
Click to expand...

Sounds Good

Lucky You, that's the 1968 9.2:1 c.r. 318, with the flat top, valve relief cut pistons, and full floating rods.

Yep, 302s will bolt right on, and if you can locate an aluminum LD4B (318) then you will have it made.

We all love the 340 cam, that will make a nice driver.

Good luck on the project.

'68-'69 318 pic below, stock bore, save those pistons!

318 3.jpg
 
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The thing is, it's probably got some bore taper and needs to be bored, so you'll have to have a set of pistons. But if you buy a core 360 or even a 340, the chances that it will need a new set of pistons is highly likely too. It's just a chance you take purchasing used engines.
 
318 will run good too with the stock '68 open chamber heads at 9.2:1c.r., if you can't find the 302s.
 
Do not assume anything, for example, that it needs overbored or new pistons.

However, with machine shop labor, you may be better off doing a Magnum swap.

That's a 100 HP increase if you don't rebuild the Magnum (and you can find them almost all day long that don't need rebuilt).
 
YY1 said:
Do not assume anything, for example, that it needs overbored or new pistons.

However, with machine shop labor, you may be better off doing a Magnum swap.

That's a 100 HP increase if you don't rebuild the Magnum (and you can find them almost all day long that don't need rebuilt).
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And they're a lot easier to find than LA 360s/340s. I personally have not seen an older carbed small or big block with any mileage that didn't have pretty significant bore wear, but it's not impossible to happen.
 
From the other extreme- Also don't assume that it's even rebuild-able.
 
Take a look at posts from 318willrun, he does some great low dollar performance builds. His instructional YouTube videos are pretty damn good for the do it yourselfers. 65'
 
Can the OP be a bit more specific on how it runs now?

Could be any number of things affecting quality or performance.

Is there a guess or estimate of actual mileage?

...and perhaps the budget.
 
YY1 said:
Do not assume anything, for example, that it needs overbored or new pistons.

However, with machine shop labor, you may be better off doing a Magnum swap.

That's a 100 HP increase if you don't rebuild the Magnum (and you can find them almost all day long that don't need rebuilt).
Click to expand...
The magnum swap was one of the first things I thought of after I decided a 340 swap was out of the question. My problem was that I have some parts (manifold and headers mostly) that I wanted to reuse. I understand that the headers will bolt up to magnum heads but the manifold won't. I guess I could sell that to offset some costs but upgrading the cam gets a bit costly.

I think I'll swing by the local Pull N' Go salvage yard on the way home from work tonight and see what they have. They show 18 various 2003 and earlier Ram pickups, Dakotas, Durangos, and Ram vans in their inventory. Maybe one of those has a magnum in it. They price V8 engines at $299 plus $85 core charge. I'll probably see a lot of empty engine bays where magnums once sat.
 
Oh, hell you're only a few hours from me.

Might also look on CL for running, driving trucks.

Did you get that Dart from a guy in Tampa that also had a convertible?
 
YY1 said:
Can the OP be a bit more specific on how it runs now?

Could be any number of things affecting quality or performance.

Is there a guess or estimate of actual mileage?

...and perhaps the budget.
Click to expand...
A couple of buddies of mine messed with it for awhile. One of them owns a body shop and they were playing with it before I had it brought down to me in Florida. I have a video clip that I can't seem to upload here but it shows it running pretty good after they changed the fluids and replaced all the fuel lines and the gas tank. It was idling smooth and sounded pretty good. They sent me pics of the sludge in the pan before they changed the oil and after seeing that, I still think a refresh is in order. I'm sure the carb needs rebuilt and they didn't do a lot of tuning on it. It says 74k on the odometer and I haven't found anything that indicates that's not original or that the odometer rolled over. It's original paint on it too and the build sheet was still under the back seat. It sat so long I think mice set up residence in it so all the carpet was thrown out and the front seat upholstery is shot. I have not really determined a budget for the whole project but as for the engine, I wanted to pull it to clean up the engine bay and the engine. The engine could use paint but I'm not going to paint an old engine. That's where the refresh idea started to take root. Then I decided since I can't really afford to make it a 340 4 speed car that I'd just go low budget but solid and reliable. If a magnum swap is cheaper, then that's the route I'll go. The whole plan is still kind of fluid. I do have a pair of quarter skins (probably only need part of those) and trunk drop offs that I need to install and I think I'll also need to buy outer rear wheel housings and probably outer rockers.
 
YY1 said:
Oh, hell you're only a few hours from me.

Might also look on CL for running, driving trucks.

Did you get that Dart from a guy in Tampa that also had a convertible?
Click to expand...
My Dart came from Indiana and was originally purchased in Cincinnati, Oh.
 
See if the '68 318 still has the cast iron water pump on it. Lower radiator hose mounts on the driver's side. Timimg marks on the passenger side.

Cast iron water pumps came factory in '68.
 
"Unmolested" finds are awesome.
 
Another vote for a 360 Magnum. With the 3.58 inch stroke its a poor mans small block stroker. The bigger stroke is like using a longer wrench to loosen a bolt instead of a shorter wrench. A lot more leverage to turn that crank resulting in a superior driving experience. So its not the extra cubes its that leverage to move the heavy street car. The bigger bore also allows the heads to breath a lot better. You'll be able to get away with less rear gear and less converter too another plus.

If it was my car 360 Magnum dressed up to look like a 340.
 
If you're not trying to give it a major boost in horsepower, I'd keep it simple. Keep what you have, a few minor add-ons, and freshen it up. You mentioned keeping it reliable and inexpensive. In that respect, I would want to keep it fairly stock and easy to remember which parts to buy in the future. Having parts from all sorts of year and model sources leads to confusion, wrong parts ordering, and having to modify things to fit. On a mild engine, forget the headers. All the Hedman headers I've seen fit poorly and hung down too low, to where they always had smashed pipes from bottoming out in dips. To me, the slight improvement in performance wasn't worth the hassle in installation, interference in working in the engine compartment, and cooked plug wires. Keep the compression ratio low enough to run pump fuel, 340 purple shaft cam would be fine, double roller timing set, high volume oil pump, and call it a day. If you're looking for performance, do a 360 swap, and all the conversion stuff required to do it. Shift kit the 904 and a maybe a slight stall increase. Your next concern will the rear end once you get the engine/trans done. A slant 6 will blow up a 7 1/4, so, it's just a grenade waiting to go off with a V8. An easy performance upgrade (and related decrease in fuel economy) would be to go with a stronger rear end, and a lower gear set. You'd be amazed how much extra acceleration power you can get by installing 3.55 or 3.91 gears, even with a stock engine. Your freeway cruising RPM will increase doing that though.
 
Stock '69 318, 230 hp, 9.2:1 c.r. stock cam, added the 4 bbl. Woke it up nicely.

Stock manifolds, single factory exhaust. Having the 4 bbl secondaries to play with added a whole new dimension to the car vs the stock 2 bbl that it came with.

69 StPaul 2019.jpg
 
George Jets said:
Stock '69 318, 230 hp, 9.2:1 c.r. stock cam, added the 4 bbl. Woke it up nicely.

Stock manifolds, single factory exhaust. Having the 4 bbl secondaries to play with added a whole new dimension to the car vs the stock 2 bbl that it came with.

View attachment 1716000653
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That's a pretty car! I have a LD4B and a 650 AVS2 to add to my 70 teen. I already have duals. It runs so nice now I hate to mess with it.
 
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