5.7 or 6.? in a 73 charger

[chargerrt340]

I am reading all of the Hemi Swap posts and I am trying to decide on which engine I should go with. I have a buddy with a 2011 srt8 5.7 and he think that engine is amazing. But I can't decide on amazing or godly!

What are the pro's and cons of each?

I want a weekend sleeper that should be taken seriously, yet can do a 300 mile trip with decent gas mileage.

 

[lxmodguy]

If they have an srt in 2011 it is a 6.4. The average guy will be more than happy with a 5.7, they will outrun your average big block and get decent gas mileage when combined with the right transmission. Good luck finding a 6.1 these days.

 

[chargerrt340]

Besides horsepower is there any pro's to a 6.1/3/4? Are they harder / easier to install?

I am looking to start buying the parts to do the swap, K member, A/C, oil pan, ...... but I need to decide on the power plant first.

 

[sleepar]

7.0 would be the only hemi

 

[HT413]

There are a few guys here that have done the swap. Maybe they'll chime in. Darius, lxmodguy and a few others.

 

[5.7 hemi]

The 5.7, 6.1, 6.2, 6.4 are dimensionally the same, so no issue's there.

 

[Modern Muscle]

The 5.7, 6.1, 6.2, 6.4 are dimensionally the same, so no issue's there.

Correct none are harder then the other IMO

 

[lxmodguy]

my advice would be to buy a control freak front end with gen3 motor mounts. Call Dave at modern muscle, get one of the 5.7 motors he has available, have him port the heads and put a small cam in it, but the ecm and harness from him.........rock and roll from there.

 

[chargerrt340]

What is the benefit to installing the independent front suspension. I am chiming in on another forum post and asking the same question, and getting the answer it is completely unnecessary. Old school v new school mentality! Does it help the ride that much, and I take it, the engine mounts, and K member are specifically designed for the Hemi addition?

Sounds like control freak is making this swap easy for a price.

- - - Updated - - -

Why the 5.7 over the 6.1?

 

[kb67mopar]

5.7 is a whole lot cheaper than a 6.1 or 6.x engine. But installation is all identical....same block...(not counting bore size etc).

Modern suspension with coil overs gets rid of the torsion bars for more room and is more tunable for better handling. Beyond that not any major benefit to removing the stock stuff if you don't plan on corner carving.

 

[chargerrt340]

How come the 6.1 is so much more expensive? Is it just more horsepower?

 

[lxmodguy]

What is the benefit to installing the independent front suspension. I am chiming in on another forum post and asking the same question, and getting the answer it is completely unnecessary. Old school v new school mentality! Does it help the ride that much, and I take it, the engine mounts, and K member are specifically designed for the Hemi addition?

Sounds like control freak is making this swap easy for a price.

- - - Updated - - -

Why the 5.7 over the 6.1?

Helps the ride, but most importantly creates a TON of room. Improves fitment on everything. Gets rids of the big ole steering box and replaces it with rack and pinion. The car will steer better, drive better, and all around be better

 

[kb67mopar]

How come the 6.1 is so much more expensive? Is it just more horsepower?

Yep I think 425 is the stock number. 6.4 I think was 450.

 

[Modern Muscle]

How come the 6.1 is so much more expensive? Is it just more horsepower?

More HP, Better Parts, IE Forged Crank, light weight valves, Piston squirters Ect... The 6.1 is 425HP at the crank and the 6.4L is 470HP

 

[chargerrt340]

I don't know why but I am digging the 6.1 or 6.4. Might be more money but I am leaning towards more "Over-Time" at work and doing it right, right off of the bat!

 

[usaroadrunner]

There is another member on here Darius and he said his 5.7 hauls the mail. I have the 6.1 so mine should do even better. I drove a 6.4 charger and that thing was pulling real hard in a 4200 lb car. I would have to say that 6,4 in yours would fly all stock. HEMI POWER. good luck with your build.

 

[the mississippi madman]

Besides horsepower is there any pro's to a 6.1/3/4? Are they harder / easier to install?

I am looking to start buying the parts to do the swap, K member, A/C, oil pan, ...... but I need to decide on the power plant first.

6.1 has a thicker cyl wall so it can handle more pressure from a supercharger than a 6.4 can

 

[chargerrt340]

I am going to call control freak and ask if they have a kit for a 73 B body, their kits only work for up to a 72.

I am liking the 5.7 fuel shut off system for increased MPG 15/23 and 340 HP

The 6.1 lacks this system but still pushes 425 HP 13/18

The 6.4 gets best of both worlds with 470 HP and MPG 14/23


All of this of course is in relationship to a built SB or BB with horrible MPG and a kick *** Cam and awesome exhaust!

 

[kb67mopar]

I am going to call control freak and ask if they have a kit for a 73 B body, their kits only work for up to a 72.

I am liking the 5.7 fuel shut off system for increased MPG 15/23 and 340 HP

The 6.1 lacks this system but still pushes 425 HP 13/18

The 6.4 gets best of both worlds with 470 HP and MPG 14/23


All of this of course is in relationship to a built SB or BB with horrible MPG and a kick *** Cam and awesome exhaust!

If those are mpg numbers from a challenger or charger they will get better in a B-body. Believe it or not but those cars are heavier. Also any engine coupled to a manual transmission does not come with or work with MDS. So you MUST use an auto if you want the multiple displacement to function.

 

[Modern Muscle]

MDS will only work with the 545RFE (Ram 1500) Trans option