Author Topic: installing a 5.7 new hemi in 71 cuda  (Read 10988 times)

Offline Dodgegrl97

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installing a 5.7 new hemi in 71 cuda
« on: June 17, 2011 - 12:20:42 AM »
how hard is it going to be to drop a 5.7 hemi in a 71 cuda? i bought a shaker set up & hood at the nationals that I'm putting on the car as well. the car is hardly a shell at the moment so alter things at this point "should" be easier. Any suggestions????
Dana

"Yes I know there is a dana rear end and no I was not named after it"

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Offline Chryco Psycho

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Re: installing a 5.7 new hemi in 71 cuda
« Reply #1 on: June 17, 2011 - 10:41:34 AM »
not having done this yet I believe there is a bolt in mount kit to bolt it onto you K frame , the problems come in with tranny , you can bolt a small block 727 or 904 on the Hemi which fit the car but if you use the 545RFE you need extensive floor mods to fit it . you also need a stand alone engine computer available from Mopar , Bouchillon & a few other peole to run the engine without the rest of the car or truck . As for the shaker hood you need to build some kind of mount for the scoop & ducting to feed air into the engine .

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Offline heminut

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Re: installing a 5.7 new hemi in 71 cuda
« Reply #2 on: June 19, 2011 - 04:52:30 PM »
Use the TTI motor mount plates and headers and it's a bolt in. Post what kind of induction and tranny you intend to run and I can give you a lot more info on how to do your setup. :thumbsup:
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Offline Road_Runner

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Re: installing a 5.7 new hemi in 71 cuda
« Reply #3 on: June 19, 2011 - 07:15:51 PM »
Use the TTI motor mount plates and headers and it's a bolt in. Post what kind of induction and tranny you intend to run and I can give you a lot more info on how to do your setup. :thumbsup:

What engine did you have before and how would you compare the two now?  That is a super clean looking install.  Doubt I would go there myself but I love the look!  And to be able to say, "Yeah, its got a Hemi", .... Priceless!!  :ylsuper:

Later, Jim
1970 383 Roadrunner Tor Red
1973 318 Barracuda Mist Green
2014 Mustang GT/CS Convertible All Black

Offline heminut

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Re: installing a 5.7 new hemi in 71 cuda
« Reply #4 on: June 20, 2011 - 02:25:57 PM »
I had a 392 Chrysler hemi in there and it was a real shoehorn job. Those engines are so wide I had to run manual steering because the power steering box was too big, and the right side valvecover was only 1/4" from the shock tower! The 392 was a torque monster but the 5.7 in there now feels like it has just as much power and it is 200 lbs. lighter!
1970 5.7 Hemi Cuda

Offline ragtopdodge

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Re: installing a 5.7 new hemi in 71 cuda
« Reply #5 on: June 20, 2011 - 02:40:52 PM »
XV Motorsports makes an intake that works for Shakers:

http://cgi.ebay.com/ebaymotors/XV-6-1-Mopar-HEMI-Intake-Manifold-E-F-I-/330287362122?pt=Motors_Car_Truck_Parts_Accessories&hash=item4ce6a9304a

of course that is more $$$ b/c you'd need fuel rails, throttle body, etc.

To use the shaker, you can just permanently mount it on the hood; 'course it won't "shake" then.

why 5.7?  Go with a 6.1 junk motor or crate.  They're not THAT much more than a 5.7.  Steel crank, better heads, etc.
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Offline moparmaster

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Re: installing a 5.7 new hemi in 71 cuda
« Reply #6 on: June 22, 2011 - 01:43:16 PM »
Seems like the motor might be the cheapest part of the conversion!  You have to run an expensive intake if you want to run carb(s), spend tons on getting an ECU and wiring harness to work the coils, then buy the mounts, headers, a smaller starter, and all the sensors for the ECU to communicate with the motor.  Too bad you can't run an old style distributor.

Offline heminut

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Re: installing a 5.7 new hemi in 71 cuda
« Reply #7 on: June 22, 2011 - 02:14:55 PM »
XV Motorsports makes an intake that works for Shakers:

http://cgi.ebay.com/ebaymotors/XV-6-1-Mopar-HEMI-Intake-Manifold-E-F-I-/330287362122?pt=Motors_Car_Truck_Parts_Accessories&hash=item4ce6a9304a

of course that is more $$$ b/c you'd need fuel rails, throttle body, etc.

To use the shaker, you can just permanently mount it on the hood; 'course it won't "shake" then.

why 5.7?  Go with a 6.1 junk motor or crate.  They're not THAT much more than a 5.7.  Steel crank, better heads, etc.


6.1 hemis are a LOT higher priced than the 5.7's! You can find a 5.7 in the $1000 to $1500 range easily, and you would have to look long and hard to find a 6.1 for anything less than $3000. Most 6.1's are $4000 and up.

The link you posted is for a 6.1 intake, which is different than the 5.7 intake. If you go to XV's Ebay store you'll find that they have no 5.7 intakes listed. I don't know what their issue is with the 5.7 intakes but they never seem to have them in stock. They strung me along and sat on my money for about 8 months on a 5.7 intake, telling me every other week that they expected them in within a couple of weeks. I finally got my money back from them. Just after I got my refund they put a listing for 5.7 intakes on Ebay showing they had 10 available. I contacted the first buyer on the auction and he said they told him the same thing,"We will have them in a couple of weeks." I contacted Ebay on the matter and they shut down XV's auction!
1970 5.7 Hemi Cuda

Offline heminut

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Re: installing a 5.7 new hemi in 71 cuda
« Reply #8 on: June 22, 2011 - 02:29:43 PM »
Seems like the motor might be the cheapest part of the conversion!  You have to run an expensive intake if you want to run carb(s), spend tons on getting an ECU and wiring harness to work the coils, then buy the mounts, headers, a smaller starter, and all the sensors for the ECU to communicate with the motor.  Too bad you can't run an old style distributor.

Indy Cylinder Heads has a modular intake with interchangeable top plates for single 4 bbl, dual 4 bbl or 3 deuce for $399. You can also find the Edelbrock dual 4 bbl intake for about the same price. The MSD Hemi 6 controller and wiring harness is about $650 plus a carb and electric fuel pump. That's quite a bit cheaper than the cheapest setup to run fuel injection by the time you figure in the cost of the controller, harness and high pressure fuel system.

As for the mounts and headers you can run some of the factory exhaust manifolds to save money and you have to buy the mounts or fabricate your own irregardless.

Fact of the matter is, your going to spend some bucks to swap in a Gen III hemi no matter which way you go on the induction and ignition but these engines have so much potential it is worth it!
1970 5.7 Hemi Cuda

Offline moparmaster

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Re: installing a 5.7 new hemi in 71 cuda
« Reply #9 on: June 23, 2011 - 03:13:54 PM »
Good tips on where to save money heminut.  I was thinking of doing this conversion with a 5.7 but couldn't seem to find all those parts within my budget.  I just got back from dropping my numbers matching 318 off at the machine shop to be rebuilt and have Magnum heads put on!
  Maybe my next project will get the 5.7.

Offline johns cuda shop

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Re: installing a 5.7 new hemi in 71 cuda
« Reply #10 on: June 23, 2011 - 03:44:06 PM »
I am doing a gen 3 hemi conversion myself.There is a great Thread over on Moparts on a gen 3 Hemi conversion on a 71 cuda http://board.moparts.org/ubbthreads/showflat.php?Number=3930520
71 Cuda Gen III Aluminum 426 Hemi T56 6 speed 4.10 8.75 Modified & Lowered RMS coilover suspension Wilwood discs