Hellcat or a 6.4 hemi engine swap.

[Flchallenger]

Going to pull a 440 and put in a modern hemi. Tried of issues with old technology. So I am trying to decide between a hellcat 717 hp or a 6.4 Are they intercoolers a problem to install. I saw a thread where I guy said there are 4 intercoolers that have to be mounted but that was the 800 hp engine. Also had trouble with it staying in limp mode. I am thinking the 6.4 would be easier to install with less headaches. Can anyone point me to post where someone has done this. Any advice is appreciated. Already have a tkx 5 speed with dana rear end with 391 gears.

 

[Katfish]

How do you plan to drive the car? Track only, cruiser, show only......
I went from a 340 to a 5.7 with only 400hp.
Honestly I can't image having 700hp and driving the car regularly.
If you only want to go to local shows and pop the hood, go Hellcat.

 

[1973CudaKJH]

Going to pull a 440 and put in a modern hemi. Tried of issues with old technology. So I am trying to decide between a hellcat 717 hp or a 6.4 Are they intercoolers a problem to install. I saw a thread where I guy said there are 4 intercoolers that have to be mounted but that was the 800 hp engine. Also had trouble with it staying in limp mode. I am thinking the 6.4 would be easier to install with less headaches. Can anyone point me to post where someone has done this. Any advice is appreciated. Already have a tkx 5 speed with dana rear end with 391 gears.

I am in process of the Hellcat install in a Cuda. It has been "a journey" to get it put in car. You have the oil intercooler, 2 water to supercharger intercooler (A small secondary with an independent pump). Costing a fortune to do. Unless you don't mind spending the money, I would recommend the 6.4. Good performance at significant savings.

I don't regret my Hellcat install as I knew up front it was going to be very expensive. I was still surprised.

Look at my posts and you can see the problem with available room in engine bay. You will have to make custom brackets for all the accessories and install extra intercoolers in fender wells.

Whatever the route you go enjoy and good luck.

 

[Flchallenger]

I have come to the conclusion I should go with a 5.7 or 6.4. The additional cooling needed for the hellcat is more than I want to get into. I going to drive on the street some strip, no car shows. With that in mind are there any issues with gettting drive angles setup. I have a 440 now with a tkx 5 speed and the tail of the trans is down 3 degrees and can't get it up to 2 degrees up like stock. Have fought a lot of vibration issues. Still not quite right. I have a QA 1 tublar k frame. Are there problems with a stock power steering box?

 

[1973CudaKJH]

I have a Schwartz Performance Chassis with rack and pinion steering & didn't have any problems with drive angles. Once you change engines to modern Hemi III it might cure angle problems.

I have a 1974 Jeep CJ5 that I did a frame off restoration and didn't modernize power train or suspension, and I forgot how awful the vibrations are. It was like that when it was new also.

Keep me posted. I'm always interested.

I still got a lot of dialing in to do, and I also need advice regularly.

 

[R4Sedan]

Have you ever driven anything with a Hellcat motor. If you haven't I suggest you do so first. Even with all the technology you can't keep them straight. So then if you put that engine in something with out any, your really gonna have a problem. I think the 6.4 would be perfect. I still suggest you drive one if you get a chance. There's no word to describe it. Freaking blast.

 

[Katfish]

Have you ever driven anything with a Hellcat motor. If you haven't I suggest you do so first. Even with all the technology you can't keep them straight. So then if you put that engine in something with out any, your really gonna have a problem. I think the 6.4 would be perfect. I still suggest you drive one if you get a chance. There's no word to describe it. Freaking blast.

You are spot on, my SIL has a 392 T/A that has 500hp, it is outright scary with the traction control off at anything below 40mph. And people forget these new Challengers weigh almost 1000lbs more than the older models.

 

[Sal C]

I wanted a Gen III and opted for the 6.4L. My Cuda will be a street/show car. Many videos on YouTube suggest the 392 has plenty of power and fun to drive, that's what I'm after. I mocked mine up, fit easily with the Tremec TKX. Only issue I had was I had to notch the torsion bar crossover frame a bit to accommodate the TKX shifter mechanism. Can't wait to finish my bodywork and drive this thing...

 

[mayhem]

You are spot on, my SIL has a 392 T/A that has 500hp, it is outright scary with the traction control off at anything below 40mph. And people forget these new Challengers weigh almost 1000lbs more than the older models.

There is a good reason why so many of these Gen III Hemi's come from wrecked cars...

 

[1973CudaKJH]

Mighty sweet looking ride and the amazing fit of the 392. What color are you going for? My Hellcat swap is getting ready for paint as we speak. As you can tell by engine bay, I'm going with Sassy Grass Green.

Please send pictures are you move forward.

 

[Flchallenger]

Now can anyone point me to a new 6.4 hemi. I understand they are on back order. Stellanis just decided to back to the hemi's so I am trying find a source for one. I talked to Randy at Bouchilon and he was told it's a possibly 2 to 3 months but if they are going to need them for cars and trucks they will come first. I looked at a company called Black bird and they build real high end race engines but could do a 6.4 pushing 600 hp and they build a 700 hp. 16 to 18k then there is bluepring that builds a 600 hp for 16 k. I am sure the engine from Black bird would be top notch they are talking 3 months to get one. They have short blocks in stock to build. Any ideas? i have had this car 20 years while it's been tore apart rebuilt with rebutlt storker motor that kept blowing head gaskets. Looks like it's got several cracked cyclinders. It's been rebuilt 3 times new heads, most expensive radiator with dual fans out there. But it does push 650 hp when it goes. Which generally has been about 100 miles. I have put about 2000 miles on this car since I have had it. It's not a trailer queen it's a shop *****. I just want to put something in that I can actually drive before I die. I am sure a lot of you understand.

 

[Katfish]

Give these guys a call, got my crate motor from them.
I believe they are the largest reseller

Mopar 6.4L 392ci Hemi Crate Engine: SKU 68303090AC

 

[Flchallenger]

Thanks I will give them a try.

 

[BSG]

Have you ever driven anything with a Hellcat motor. If you haven't I suggest you do so first. Even with all the technology you can't keep them straight. So then if you put that engine in something with out any, your really gonna have a problem. I think the 6.4 would be perfect. I still suggest you drive one if you get a chance. There's no word to describe it. Freaking blast.

Thats why they are everywhere on fbmp the easy finance for young kids is a quick recipe for a hellcat and pole or tree

 

[AUSTA]

I have a 6.4 in my 72 RR clone plenty of low down grunt smooth as on the freeway

 

[ItsJustMe]

I have a 6.4 in my 72 RR clone plenty of low down grunt smooth as on the freeway

View attachment 142544

6.4 is the way to go. Plenty of power and 1/4 the price. @AUSTA what intake setup are you using. Looks like a good fit. Is the filter a 4 inch ID?

 

[AUSTA]

BBK on ebay BBK Fits 11-20 Dodge Challenger/Charger 6.4L Hemi Cold Air Intake * Blackout

 

[PLUM_72]

Something else to consider here. Those that opt for the Hellcat engine or better, you might want to read your insurance policy. Haggerty has some limitations on horsepower up to 650hp. Not sure what haapens if you have more than that. Likely higher rates or something else. Perhaps other places may not have that restriction. I was shocked to read the 650hp limit in my policy.

 

[1973CudaKJH]

Good information on Haggerty HP limits.

I have collector car insurance on my Redeye Challenger with 797 HP with another company. Also, I recently spoke to them about insurance for my 73 Cuda project with a Hellcat and with a valuation of $200K and got an informal quote of $1200/year when it is finished - someday hopefully soon

 

[Flchallenger]

Well I haven't gotten to far on this. Ended up ordering a engine from a race engine builder. Was going to be a 6.4 ported heads and cam producing around 600hp. After 2 months waiting he puts videos up tuning on the dyno. I didn't return a call to him on sat night and sunday morning I get a text saying he is not going to sell me the motor claimed I was sketchy. I don't know sent him 8k down payment on a 16 k motor. So he says he will mail me a refund for the down payment. I went with him on the advice of a friend that met this guy at a mopar drag event and spoke highly of him. Also he would dyno and setup the controller which I have no experience with so I was willing to pay up for more power and fewer headaches. I have been trying to get this car going for 20 years and over 200k invested in it. I am at my wits end. There is a hurricane coming so maybe I will have it towed to the beach parking and collect the insurance when it washes out with tide. The world has really turn to ****. I don't know what I am going to do.