Stock 340 Cam Tech Question

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ricks70dart

ricks70dart

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I bought this cam from a guy several years ago brand new in the box. He said this cam was the 68 4 speed cam only used one year.I,am rebuilding my stock 340 out of my 70 Dart numbers matching. my car is an automatic. My question is which cam this is, I scanned spec sheet just want to make sure on what I have before using it.Would like the specs for both factory cams but can't seem to find them. If it is the hotter 68 cam I think I will use it any way in my stock engine and hope it will perform a little better and sound better.Any info greatly appreciated
 

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I can't see the attachment so I'll throw some numbers up. I get them from Petersen's Musclecar Classics dated 1985

The 340 Auto in 68 had a lift of .430 intake and .445 Exhaust with a duration of 268 Intake and 276 Exhaust.

The Manual had a lift of .445 Intake and .455 Exhaust with a duration of 276 Intake and 284 Exhaust.

That's all I know.
 
Just by the lift it looks like the automatic cam to me.
 
That's not either. But closer to the stock 340 auto.

It's not an exact copy of the original 340 cam, but is close. A very nice cam for the street and has nice torque. I used it in a 79 Warlock II with 9.2 compression, Wiand dual plane intake, carter 4 bbl, and headers.

We gained over 2 mpg on the highway when pulling our car on a trailer and much more torque than the stock cam. Our truck could pull everything easily.

After we sold the truck, the guy who bought it went off roading with a couple of chevy buddies of his. They used to give him **** for driving a Dodge. One of them got stuck, and our old Dodge truck pulled that Chevy out easily without even working up a sweat.

They never gave him **** about driving the Dodge truck again....


If it is still brand new and you don't want it, give me a PM....
 
Stock 68 340 Auto cam:

Lift: .429"/.444"
Duration: 268°/276°
Overlap: 44°

IVO: 22° BTDC
IVC: 66° ABDC

EVO: 74° BBDC
EVC: 22° ATDC


*Specs from 68 Plymouth service manual...
 
ricks70dart said:
I bought this cam from a guy several years ago brand new in the box. He said this cam was the 68 4 speed cam only used one year.I,am rebuilding my stock 340 out of my 70 Dart numbers matching. my car is an automatic. My question is which cam this is, I scanned spec sheet just want to make sure on what I have before using it.Would like the specs for both factory cams but can't seem to find them. If it is the hotter 68 cam I think I will use it any way in my stock engine and hope it will perform a little better and sound better.Any info greatly appreciated
Click to expand...

Be careful it is not a "stock class" blueprint cam, slam valves open and slam them closed. They are very hard on valve springs. Good for a race car but a bit hard on the valvetrain for a street car. Do you have a picture of the cam?
 
I've got the 68 formula S 4 speed cam in my 69 dart swinger automatic trans . It needs a little torq converter but runs well. It also has some lope to it .
 
In the 1968 Barracuda magazine ad called "Shortcut".. the specs for the 340 cam with a four speed were claimed to be,
intake lift .445 duration 284
exhaust lift .455 duration 292
60 degrees of overlap
they said that the auto box couldn't quite cope. so it got the 268 cam we all know
 
hi, found real cam specs in a real mopar service manual, 1968 ..manual trans cam, is 276/284 duration.52 deg overlap, .444 int lift, .453exh lift. the auto cam is , 268/276 duration, 44 deg overlap..429 int lift, .444 exh lift.
 
Let's not forget you cannot literally compare cam numbers from two different manufacturers, at least not back then
 
I have seen people talk trash on both those 340 grinds all my life. The fact of the matter is either one will rev well past 6K and keep pulling doing it. They idle good, pull a good vacuum signal and have a very broad torque curve. That was a tall order back then and it still works well today.
 
RustyRatRod said:
They idle good, pull a good vacuum signal and have a very broad torque curve. That was a tall order back then and it still works well today.
Click to expand...


No it doesn't....


Don't you know the laws of Physics has changed since then.... #-o


They changed on 4/20/96 and haven't been the same since....
 
The cam was made when Harvey Crane still owned the company in Hallandale FL. IMO the quality, metal/heat treatment, and grind would be great for a nice street car.
 
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