Progress Thread Lets Frankenstein a 1998 Cobra into a 1968 Coupe!

[Cool Beans]

Back in March of 2019 I had the great idea to buy a complete used and abused Cobra to swap into my 1968 "C" code coupe. The 68's engine and trans were worn and needed to be rebuilt anyway, I wanted to upgrade to R&P steering, and better disk brakes. I was thinking about a T5 swap already and I wanted to convert to EFI (I hate carbs). I was aiming for a modest low 300hp on the build, so a slightly modded 32v 4.6l fit the bill.

The build is nearly complete. I have driven the car up to 3rd gear around the block for a total of 1840 feet...and I only stalled out once I have put together an abridged series of pictures (127) and 1 video from my project and will upload them in chunks over the next couple days.

So I found a company called AJE Racing that makes a front and rear suspension system that allows me to basically (I laugh, it sounds so easy) bolt in the rear axle with coil overs and converts the front end to a late model "K" member style MacPherson Strut setup. I did not use their kit for the front but opted to put together my own using their K-member and lower arms. There is a Facebook page for AJE conversions if anyone is interested.

Engine is a 4.6l all aluminum 32v Cobra engine from a 1998 Mustang. I rebuilt it with a 10.4:1 CR, IMRC deletes, EGR deletes, stock manifolds, and an offroad x-pipe. I'm using the T45 transmission with a semi custom hydraulic clutch conversion. A shortened Aerostar Van aluminum driveshaft was used to connect to the coil sprung 8.8. The rear axle was rebuilt with 4.10 gears. I'm using QA-1 double adjustables in the rear with 170lb springs and Strange single adjustable in the front with 175lb springs. I'm using pretty much all the engine, drivetrain, steering, brakes, emergency brakes, hydroboost, wiring harness, cooling system, and exhaust from the Cobra. Fuel supply is a Hyperfuel conversion I installed in the stock tank. Battery was relocated to the trunk. I just realized I have no pictures of those

I still need to make an intake tube that fits, align the steering, mufflers, tires, then drive the outta it! Teaser pic of the car in the driveway over the summer. Garage pictures are as it sits after I drove it around the block last weekend

 

[Cool Beans]

I'm skipping the tear down of the '68 since pretty much everyone here has seen a 289/c4 removed and an empty engine bay. First picture is the start of the conversion with the centers of the towers hacked out and the k-member dry fitted followed by the dry fit of the rest of the front end. The rest of the pictures have been organized in a more linear progression of the build than the undirected chaos that is my normal mode of approaching a big project

 

[Cool Beans]

After trimming the towers more and repairing the top of the aprons, the first test fit of the engine and transmission. It's tight, but doable. When the car goes down for the actual restoration, I'm thinking of shaving the firewall on the passenger side. IF...big IF...if I decide to have Heat/AC, I'm going aftermarket kit. They are so much smaller and compact.

 

[Cool Beans]

Final fitment was good, engine/trans back out for plating of the towers. A little grinding, bondo, and paint...looks like a million bucks!

 

[Cool Beans]

Second fitting of the dressed and rebuilt engine. It's like trying to cram 8 lbs of crap in a 5 lb bag. But those notched towers actually provide a lot of room!

 

[wicked93gs]

I always did love that engine(did the swap once too....mostly, never got a running driving car, but did cut out the shock towers, put in a MII suspension, etc and get it to within a few weeks of starting) I used the Mark VIII block though with a Cobra intake(that is one expensive intake to find used). What made you use the SN95 Radiator though?

 

[Cool Beans]

I always did love that engine(did the swap once too....mostly, never got a running driving car, but did cut out the shock towers, put in a MII suspension, etc and get it to within a few weeks of starting) I used the Mark VIII block though with a Cobra intake(that is one expensive intake to find used). What made you use the SN95 Radiator though?

Yeah they are, lol. I used the radiator mostly because it's sized for the engine, works with the stock fan, outlets are correct, and I already had it so it cost me nothing. Even reused the radiator hoses and thermostat housing. I made a rail out of angle and 3/4" square tube covered in foam tape to set the radiator on. The top is a similar bracket (needs to be modded since I raised the radiator a 1/4"). I spliced in a 16lb radiator cap and fill from a 2005 Durango and will plumb that to a nicer overflow bottle instead of having a sealed expansion tank.

 

[Cool Beans]

So where did I leave off last night...
Ok, so I stripped the complete wiring harness out of the Cobra...Headlights to Inertia switch. Basically, I laid it out on the driveway and starting cutting away what I needed. I can't begin to explain to you how I knew what to do other than I just kind of knew what to do. I don't really have a wiring diagram, but I do have a pin-out sheet and a .pdf Haynes manual and a couple of saved posts from FactoryFiveForums. It's not hard if you are already familiar with EFI and car wiring There are 2 separate harness: The chassis harness that carries main power, the ECU, OBDII port, ignition power, grounds, fuse block, MAF and IAT, CCRM, Fuel pump, transmission harness, and fan (I think that's it). Then there is an actual engine harness that takes care of charging and engine management. Once I get a couple thousand trouble free miles out of this, I might rough out a complete wiring diagram for my conversion and share to the car community.

 

[Cool Beans]

These pics are actually out of the order that I'm building the car. I was jumping all over the place. After I did everything inside the car and the rear end, I came back to the front and it was time to pull everything for "final" fitment and install. I custom bent brake lines, clutch master install, tightened up all the wiring, cut and modded the radiator support to be removable, steering shaft, etc. Driver side wiring is basically done, I still have a few circuits to remove/mod on the passenger side which is why I didn't loom them yet.

 

[Cool Beans]

Continuing to make and install everything I need to with the engine and tranny out. I "duplicated" the stock cobra geometry into my '68 pedal box and so far it all seems to work great! That clutch master adapter is a copy of the expensive kits online and made out of 2" diameter exhaust tubing and some 1/8" plate.

 

[Cool Beans]

Last group of pics for now. Moving into the car I rebuilt and modded the steering column for a universal at the end. I also modded the car to accept the Cobra emergency brake handle and cut and recrimped the cables to work in the car. It works and works fantastic! First time I have owned the car and it had emergency brakes that worked.

 

[2Blue2]

This is really neat, love the picture heavy descriptions.

Carry On!

 

[Cool Beans]

More pictures! So with the engine bay empty, the next big step was to tighten up the wiring and run brake lines. I bought a 25' coil of 3/16" CuNi brake line and fittings and bent my own lines. I used the Cobra distribution block since I was using the Cobra brakes front an rear. I decided to run the lines forward and around to the passenger side instead of back and toward the fire wall. I converted the rear axle brake lines to Fox style with a single body line. Trimming, looming, and making grounds for the wiring is boring so I just have the final layout.

 

[Cool Beans]

Last Engine bay pic showing the wire loomed and steering hooked up. I found the easiest way to attach 6AN lines for the hydroboost was to braze 6AN fitting onto the stock tubing. Quick shot of the oil filter relocated and radiator hooked up. Of course the intake is too tall, but I wanted to put a hood scoop on regardless so it worked out!

 

[Cool Beans]

A couple random intermission pictures. I made my own shifter out of 1/4" plate and 1/2" tubing. I cut and bent the tubing around a dead blow hammer and actually made it to place the shifter where my hand naturally wants to be. Tapped the end for the shift knob. Cost like $6. That crap they sell online is a total rip off.

 

[Cool Beans]

Rear axle is up next. I had to pull the rear axle and suspension and remove the shock brace from the car. Other than working upside under the car, this was actually a pretty easy part of the project. This is also where I really discovered just how poorly these cars were put together

 

[Cool Beans]

Last of the build pics!

 

[Cool Beans]

So this went faster than I thought...I wish the project went like this in real life

Here's a video of it running:
View: https://youtu.be/UCkDmWV7rdA


That clicking noise is a bad alternator, and also the reason the voltage is less than 12v. Still have tweaking to do, chase down vacuum leaks, hook up a line to the fuel regulator, etc. Next project is fiberglassing an intake tube. I'll start posting regular progress pics and updates as things happen from now on. Next video will be me driving it. If you have any questions, holla!

 

[wicked93gs]

Seems like a lot of work for a coilover solid-axle rear end with all the bolt-on kits around. I have played with the idea of IRS myself using a Ford 8.8 that I have mounted in a Miata cradle....the Miata IRS cradle and control arms are fairly compact(and the track width between it an a 66 are almost identical). The only reason I didn't tackle that one was because when I measured it I would have had to change the shock and spring angle to clear the frame rails and I wasn't sure how that would affect things.

 

[2Blue2]

Burnouts?