Author Topic: Another 5.7 hemi question  (Read 671 times)

Offline 71bigblock

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Another 5.7 hemi question
« on: March 15, 2007 - 08:24:07 AM »
Im planning on getting a 5.7 and putting it in my '67 dodge.  Anywho, this is my dilemma.  I want to keep the original tranny.  Reason being is so that I dont have to modify the driveshaft, or new tranny mounts.  The 4th gear ratio for my tranny is 1:1.  If I run a 3.54 ratio in my Dana 60 with a 30" tire that I have on it now, the RPM calculator says that the motor will run a little over 2200 at 60 mph. 

Here's the question:  Is that too fast?  I know overdrive is nice, but more work when it comes to fabbing things.  I plan on driving it as much as I can when it is dry outside.  But only for cruising.  I will probably NEVER go more than 65. 

Just looking for some opinions on this subject.   :feedback:

Thanks in advance! 




Offline Chryco Psycho

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Re: Another 5.7 hemi question
« Reply #1 on: March 15, 2007 - 11:08:14 PM »
2200 RPM on the highway is Ok ,possibly on the low side,
2500at 65 is normal  typically

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Offline 71bigblock

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Re: Another 5.7 hemi question
« Reply #2 on: March 16, 2007 - 07:57:01 AM »
2200 RPM on the highway is Ok ,possibly on the low side,
2500at 65 is normal  typically

Thats good to hear. 

Now for another question for the almighty CP (or any other car tech guru)

Can I get a 5.7 hemi, and use my old 4 speed tranny from my truck?  Or will there be computer issues  IE, computer thinking that the tranny isnt there, computer not knowing how fast Im traveling, etc...  Is there a way to "trick" the computer, making it think that I have a factory transmission back there?

So many questions.   :bricks1:

Offline Chryco Psycho

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Re: Another 5.7 hemi question
« Reply #3 on: March 16, 2007 - 08:44:52 AM »
Mopar offers a stand alone engine computer for the 5.7
never tried to order it though so I do not know if it is actually available

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