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Discussion Starter #1
Those of you that have swapped your 5.7 cam with the 392 cam, I know that the MDS doesn't work at that point, but curious what your gas mileage dropped down to in city and highway? City I average about 15mpg, and highway about 23mpg.

Also, did you swap out pushrods, springs, intake and tb too?
 

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I never had MDS, 6 speed. My mileage is about 16 cty and 26hwy. I haven't driven much yet as I am waiting to get tuned.

I did springs and installed a 87mm tb and JBA shorties.
 

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Those of you that have swapped your 5.7 cam with the 392 cam, I know that the MDS doesn't work at that point, but curious what your gas mileage dropped down to in city and highway? City I average about 15mpg, and highway about 23mpg.

Also, did you swap out pushrods, springs, intake and tb too?
If you use the auto cam you will still have mds working unless you disable it with the tuner.
 

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Discussion Starter #4
Thank you both....I won't be doing the switch for a while, but just trying to do my research.
 

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I have a 12 R/T classic 6spd with JBA shorty headers,392 non mds cam,180 thermostat,Charger air tube, BB MF49CE res delete, and DS trinity with tune by Hemifever. I'm still averaging 18 to 19 mpg around town(I don't live in or around city)but have not gone on a long highway cruise yet. I used the PSI LS1511ML springs and stock pushrods, the stock 5.7 springs have a higher spring rate than the PSI do and the PSI and 6.4 springs are within a couple of pounds of spring rate from each other. So I figured if these pushrods are strong enough for the factory to ward off warranty claims they are strong enough for the cam and springs I put in.
 

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I have a 12 R/T classic 6spd with JBA shorty headers,392 non mds cam,180 thermostat,Charger air tube, BB MF49CE res delete, and DS trinity with tune by Hemifever. I'm still averaging 18 to 19 mpg around town(I don't live in or around city)but have not gone on a long highway cruise yet. I used the PSI LS1511ML springs and stock pushrods, the stock 5.7 springs have a higher spring rate than the PSI do and the PSI and 6.4 springs are within a couple of pounds of spring rate from each other. So I figured if these pushrods are strong enough for the factory to ward off warranty claims they are strong enough for the cam and springs I put in.
Good info!I didnt know i could use the stock push rods so i ordered them i think they were $100.Did you pull the heads im looking for a top end gasket kit(head gaskets and all)?
 

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No I did not pull the heads, Just pull the rocker shafts and pushrods, balancer,timing chain cover and chain and gear and tensioners, oil pump( you have to take the 4 bolts off for the pump and turn the pump clockwise enough to take out the bolt for the pickup tube, use magnet so you do not loss the bolt in the oil pan) and than spin the cam a few times to push the lifters up in to there bores and remove cam.
 

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Discussion Starter #9
I have a 12 R/T classic 6spd with JBA shorty headers,392 non mds cam,180 thermostat,Charger air tube, BB MF49CE res delete, and DS trinity with tune by Hemifever. I'm still averaging 18 to 19 mpg around town(I don't live in or around city)but have not gone on a long highway cruise yet. I used the PSI LS1511ML springs and stock pushrods, the stock 5.7 springs have a higher spring rate than the PSI do and the PSI and 6.4 springs are within a couple of pounds of spring rate from each other. So I figured if these pushrods are strong enough for the factory to ward off warranty claims they are strong enough for the cam and springs I put in.
Great info! Thanks alot for that!
 
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