Cam swap question

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scooby67

scooby67

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Hello all. I’m looking to swap out the cam in my 1969 340, 4 speed Dart. Also changing the stock intake. It has stock cast iron heads with headers. Current cam is a Crane 216/216- 454/454. Going with an Elgin 231/231- 480/480. More duration and lift.
Am I ok with the stock valve springs? Also, with the longer duration, is valve to piston clearance going to be an issue?
 
I'm sure everyone's gonna tell you to get the recommended springs.. me personally i wouldn't. I would just run it like it is with the springs that it has and if it floats too quickly, then I may put tighter springs on it.. that is definitely not the correct way to do it...
While I would check the valve clearance to piston. I would bet money that it's not even close....
 
Why and what to are you changing the stock intake to?
 
scooby67 said:
Hello all. I’m looking to swap out the cam in my 1969 340, 4 speed Dart. Also changing the stock intake. It has stock cast iron heads with headers. Current cam is a Crane 216/216- 454/454. Going with an Elgin 231/231- 480/480. More duration and lift.
Am I ok with the stock valve springs? Also, with the longer duration, is valve to piston clearance going to be an issue?
Click to expand...
How fresh are the cam bearings? I would make sure they are in could condition without flaking top or bottom.
Trans will have to come out to put bearings in.
 
Oldmanmopar said:
How fresh are the cam bearings? I would make sure they are in could condition without flaking top or bottom.
Trans will have to come out to put bearings in.
Click to expand...
The engine rebuild has less than 500 miles on it. Although it was done many years ago, the car has rarely been driven.
 
I’d put my money into a 5 angle valve job and minor porting before I’d upgrade to an aluminum intake. Best you’ll do is drop some weight with a manifold swap, maybe a minor performance gain.

Buy a cam kit from a quality cam grinder like Erson, Engle, Racer Brown etc, cam lifters and springs. You get what you pay for.
 
I would bet that the stock intake performs as well (or better ) than the Action Plus. Performer RPM would be an upgrade. I don't know your rear gear ratio , but if it's 3.23 or 3.55 I think I would stick with your existing cam. A plus: it's already broken in . You may have heard of the spate of flattened cams lately.
 
forphorty said:
I would bet that the stock intake performs as well (or better ) than the Action Plus. Performer RPM would be an upgrade. I don't know your rear gear ratio , but if it's 3.23 or 3.55 I think I would stick with your existing cam. A plus: it's already broken in . You may have heard of the spate of flattened cams lately.
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Why does the term flat cam not sound right...
It seems like a better term would be the cam went round....
 
Thats a great upgrade for a basically stock 340 , same as the 480 summit cam, check your seal to retainer clearance. I use comp 901 springs with that cam which are just a slightly heavier 340 spring.
 
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