1970 to 2012 challenger k fram

[Sean M]

I have a 1970 challenger that I’m Resto modding, I’m dropping a 5.7 HEMI and 6 speed trans from a 2012 challenger into it. I’ve heard of clearance issues and new engine mounts being needed to mount the new HEMI on the stock K frame so I was wondering if I could utilize the engine cradle and front suspension from the modern challenger on my 70?

 

[70chall440]

Anything is possible with enough work and money, but it is a long way from a bolt in deal. I believe the track (width) is pretty different, the way it mounts and how everything comes together. You are much better off using some of the motor mounts out there and bolting the 5.7 into the K frame you have.

 

[Sean M]

Anything is possible with enough work and money, but it is a long way from a bolt in deal. I believe the track (width) is pretty different, the way it mounts and how everything comes together. You are much better off using some of the motor mounts out there and bolting the 5.7 into the K frame you have.

I’ve considered just cutting out the old motor mounts and welding in the new ones, but if I were to do so I would have to pay around 200 bucks for the mounts, 250 for the center sump oil pan and pay for a oil filter adapter. I saw another thread where someone shortened the rear irs and welded it into the frame, so i was wondering if the front would be similar in fabrication?

 

[70chall440]

I have not compared them personally so I cannot tell a definitely yes or no. If you have the donor car, drop it out and look it over, it may be possible but I think it comes with a lot of other issues; the 12 uses a strut system whereas the 70 has T bars and shocks. It would take a lot of fabrication for the struts to work; read lots of bracing and sheet metal work.

Just guessing here but I think the cost of putting the 5.7 into the stock K frame is going to be minor compared to what you are going to spend in time, materials and potentially parts to get that K frame into the car. I have a 70 and a 10 and have been under both quite a bit, I could be wrong but I just don't see it being any where close to easy.

 

[70chall440]

I think mounts can be fabricated relatively easy, the pan and associated bits is another issue, you could always modify the pan you have, and/or you could notch your existing K frame and plate it in (lots of guys have done that).

Again, anything can be done with enough work, but given that you are talking front suspension it has to be right and that takes a lot of work and a lot of resources.

 

[Sean M]

Thanks, that’s the information I was looking for, what do you think about the rear end swap. I read up on a forum where a guy took a dodge irs and shortened a inch on both sides and welded it into the frame. I have all the tools to do something like that, I’m just skeptical to do something major like that.

 

[70chall440]

The rear is a little easier but you probably need a frame table to ensure everything is square. Also, you are going to need to chop the crap out of the existing frame rails to make room. If the car is on a rotisserie or something it might be easier. IMO I am not sure I would attempt it unless the 70 is gutted. You have to think about design features, here again the IRS is wildly different in design to leaf springs. There are lots of rear suspension designs out there; 3 link, 4 link, etc. Its all about what you intend to do with the car.

Again, doable but at what cost is the question. I do not think it is as simple as shortening and welding in, lots of planning and fabrication IMO.

 

[Chryco Psycho]

FYI the oil filter adapter will not work with the 70 frame there are 2 plugs in the side of the bloc you can attach hoses & put the fiter where it will fit easily

 

[moparleo]

You can buy most of what you would need in a bolt in kit. Why try to put a Honda crank into a Dodge engine ?

 

[fasjac]

Give Mancini racing a call. I believe they have some bracket kits that may help you. You’ll probably have to get TTI headers for the 5.7 though. Good luck with the build.