Switching from fwd to rwd

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Hey there, I think that this is difficult to doand was wondering mostly it it was possible. I have a 1993 chrysler imperial. I want to take out the 3.8 V6 and put in a 360 V8 from a chrysler cordoba. I was wondering that if during this process i could switch from front whell drive to rear wheel drive. Thank you for any help that you can pffer me.
Don Rugenstein

posted by  drug26

That's the only way you're going to do it because the 360 isn't going to bolt up to the transaxle or fit between the transaxle and the right inner fender.

So, all we need to do now is figure out how to install a Mopar small block and a transmission and a third member under a FWD unibody car. Without going into to much detail it's called lots and lots of custom fabrication.

So to answer your question, could you do it? Yeah but... what's the point?

posted by  vwhobo

and the cost will probably be astronomically high i bet. :?

posted by  SuperJew

Come on guys, I am in full support of a little work and creativiity. Maybe drug26 is a master welder and can cut apart the floorboards and weld in a tunnel for the driveshaft to fit into. As for "whats the point?", how about just to do it and to have pride in your creation. To answer the question, yeah, it can be done. It will take a bit of work and does not have to be expensive if you can fabricate parts yourself.

There is one way that, although not the lightest, would be fairly easy. Use a full frame vehicle to supply the chassis and then remove all the suspension components from the Imperial and place the body on the frame. Then bolt it up or weld it.

I used this method to build a 4X4 Caddillac Seville. Anything is possible.

posted by  theman352001

Well, I am not a master welder, nor do i have alot of money, and this is ust alittle project i am working on so I know that it will take time. I appreicate the support. I will keep every one posted on the process. I have another question as well, what frame do you recommed. I would also like the car to be a manual transmission.

posted by  drug26

I too fully support his ambitions. It was obvious from the questions and the way they were asked that he had no experience in this type of endeavor. I should have worded my question better though, as in what is the purpose.

posted by  vwhobo

Well, the purpose is that I really miss my rear wheel drive firebird, but that is now toast due to the fact that it caught fire. I am now back to my frist car and wanna do some mods to it. What i would like to do is change it from from a front wheel drive auto v6 :( to a rear whel drive standard v8 :twisted: . I will definitly post some before and after pics when the oppurtunity arises and I can actually afford to have this process done. Any ideas on possibly the cost? That is besides the cost of the cordoba. Again any help is apprecieted.

posted by  drug26

Either way you do this, write a check to someone else or do the fabrication yourself, the cost will be extemely high in dollars or time. You can do it the way theman did but...

He started with a fairly large, full frame, RWD car which is similar in construction and size to his donor frame (I'm guessing a '70's to '80's Blazer) so all he basically did was a body swap. Add to that the fact that on a 4x4 having the frame exposed underneath looks cool and makes the body sit higher adding to the cool factor. Please don't take that as a minimalization of the work he did, but it is much simpler than what you're looking to do.

You need to decide if you want to fit the drivetrain to the unibody or set the unibody on a frame. If you put it on a frame do you want it to sit high or are you going to channel the unibody to sit lower? What frame is dimensionally the same or are you willing to modify the frame to fit? How is the engine going to fit under the hood? I think the engine bay is too short so you'll be reworking the firewall to make it fit, in addition to the floor to fit the trans. Ah the trans, to make a manual work you'll have to come up with a three pedal assembly and a cable or hydraulic system actuate the clutch.

Let's say you don't want to use use a frame. You still have to fab a structure to reinforce the unibody and have a place to mount the drive train. Imagine if you will an NHRA Pro-Stock or Winston Cup car and how they're built. That may be a bit extreme but that's what it looks like when you make a FWD car into a RWD car without the use of a full frame donor vehicle. Whew!

Bottom line is you need to figure out which way you want to go, then get out you tape measure and do some more figuring. My honest assessment is if you want a RWD car that you can drive anytime soon, your best bet would be to go buy one.

posted by  vwhobo

vwhobo, you hit a lot of the points right on the head. There are a few clarifications though.

The Seville I used was an '84 and was FWD not RWD. This did require me to cut out a bit of material in the middle of the car where the firewall meets the floorboards to accomodate the trans. I did not have to create a tunnel however because the rest of the drive train fit between the frame rails of the '79 Bronco frame.

The other point is that the frame of the Caddy ran along the outside edge of the body. The frame of the Bronco was much narrower. At least 6" on each side. This required fabrication of brackets to meet up with the existing body mount points. You can see one of them right under the drivers door.

The main reason why is sits up so high is that the back floorboards are about 1/2" from the frame rails. I did not want to go though the hassle of channeling out the body to fit the frame. PITA.

I also did have to lengthen the frame 10" to accomodate the wheelbase of the Caddy. That is the only fabrication I had somebody else do as it was a bit more critical. Otherwise, the rest of the project was basically an exercise in learning and expanding my skills.

As far as cost is concerned, it was about $100 in steel, $100 for the caddy body, $63 for electric radiator fans (quite a bit of room between the motor and the radiator), $224 to lengthen the driveshaft, $300 for miscelaneous parts and supplies, and about $2500 into the motor.

This next number is not meant to squash you drug26. I only had the weekends to work on the vehicle because it was at my parent's place about 2 hours away. I also did not have every weekend to work on it. In total, it took about 1.5 years to get it from 2 separate vehicles to a single legal vehicle with WI issued VIN number.

vwhobo has a point in that if all your looking for is a RWD car, then it is much easier to go out and buy one. If your looking to expand your horizons, then this is a fun project. The added benefit is the attention you get when your driving it down the road.

posted by  theman352001

So it would better if instead I put it on a 4x4 frame and raised it then then I would not have to do alot of works on the floorbords because the tranny wuold fit underneath the frame. Although if i did get a a v8 no matter what size i would have to do some work to the firewall, correct. Look at this http://www.4x4hp.com/3pic.html"> 4x4 camaro think the imperial would look beter like this any way, raised and amazed!

posted by  drug26

I think we're saying it would be easier, not necessarily better. But if that is the case, I'm not sure how a 4WD Chrysler takes the place of a RWD Firebird.

posted by  vwhobo

I think you would have to do some work to the floorboards anyways unless you really raised the body up so the trans cleared the floorboards. I am not familiar with the Imperial setup or the Cordoba setup so I can't make a guess as to how much work would be needed.

My initial thought though would be that you could cut out the floorboards of the imperial so the trans fits and then cut out the hump from the Cordoba and have it welded onto the floor of the Imperial. I did this with my project, using the access pan from the Bronco and welding it onto the Caddy's floorboards. It wasn't that much of a problem.

The more I think about it, the more I think that using the Cordoba frame may be an easier way because I think it would require less extensive modifications to mount the unibody. The method I mentioned above about the floorboards is an easy solution for modifing the floorboards.

I will have to dig out some more pix to show you what I am talking about.

posted by  theman352001

All very good info, by using as many existing parts as possible you save some fabricating and have a better fitting, more factory like appearance.

The thing is the Cordoba is a unibody car so there isn't a frame to pull out from underneath. Trying to graft the Imperial upper body to the Cordoba lower body would be an exercise in futility as it's substantially wider and has a longer wheelbase. Add to that the fact that if you could successfully modify and adapt the two together, all the welding would have to be done expertly to maintain any stuctural integrity and therefore safety.

posted by  vwhobo

Not too up on my Mopar - what has frames and what doesn't - information but that is key information that is needed to do this project unless you want to section and either lengthen or shorten a frame.

The wheelbase of a '91 Imperial is 109.3". That is key info #1. You are going to need a frame that closely matches this.

I dod some quick searching on the web and found the following:

Volare / Aspen - 108.7"
1977 Jeep Wagoneer / Cherokee - 109"
Land Rovers (seems like a lot of them) - 109"
1980 - '87 AWD Eagles - 109"
Dodge Ram Vans - 109"

Didn't find many cars that were coming up with that wheelbase. If you do some more extensive searching, you may find some. One point to remember if your not a die hard Mopar fan, you can use a different make for the chassis.

posted by  theman352001

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