Hemi Swapping a perfectly good 70 Duster

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racerjoe

racerjoe

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For those not following along on my build thread, I'll highlight some of the G3 Hemi swap specifics here.

Here's a quick background. 70 Duster I've owned since 1997. I use it as a cruiser, and autocross. It's got a 408 LA in it with solid roller cam, indbrock heads and port EFI made by yours truly. 5 speed Tremec trans and 8-3/4 rear. Complete with big brakes and wheels to piss off the purists and make it stop and turn well on the autocross. You can find more info and pictures on my build thread linked in my signature.

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The title of this thread is slightly misleading as of 2 weeks ago. I was working toward the hemi swap and planning to start later in the summer. Well, my 408 killed a roller lifter, so the swap has been expedited.

The engine is an early 5.7 that was supposedly low miles. I believed it was once I tore it down to find all the bearings looked like they came out of a box. The cylinders had zero scratches and hatch marks from top to bottom.


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I re-assembled the engine with all the parts that came out with a new set of rings and a high pressure/volume melling pump.

For the heads, I did some hand porting and reused the stock valves with a fresh lap job. The camshaft is a Cam Motion Titan 2 with the recommended springs and hellcat lifters.

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Once it was assembled I started making it pretty.
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I made my own harness and it will plug into my existing firewall connector. Should be mostly plug and play.
harness2.jpg
 
I'm using the cast lakewood housing. You can see there was a small interference with the TTI header, but that was easily fixed with a grinder. Note the clearance on the starter from an early 2500 with a manual trans. This thing is smaller than the mini starter on my 408! It will fall on the floor without taking the header off too.
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I use mechanical linkage on my clutch. TTI says the Z-bar needs to be modified. Here's why. I'm making a new arm for it with a dog leg so it clears the tube.

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Forgot to mention I have an HDK suspension, so this thing will just fall into place, or at least I hope so.
 
racerjoe said:
I'm using the cast lakewood housing. You can see there was a small interference with the TTI header, but that was easily fixed with a grinder. Note the clearance on the starter from an early 2500 with a manual trans. This thing is smaller than the mini starter on my 408! It will fall on the floor without taking the header off too.
View attachment 1716240212View attachment 1716240209View attachment 1716240208

I use mechanical linkage on my clutch. TTI says the Z-bar needs to be modified. Here's why. I'm making a new arm for it with a dog leg so it clears the tube.

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Did you consider hydraulic clutch setup?
 
racerjoe said:
Nope, not for me. I made all new linkage with heim joints. It’s smooth as butter.
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Any pics of that setup?

I would love to see how you did that.

Sounds very interesting using heim joints!!
 
Super-Cuda said:
Any pics of that setup?

I would love to see how you did that.

Sounds very interesting using heim joints!!
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Check out post 197 of my build thread here --> 12:05 Garage- ’70 Duster build

To accommodate the offset for of the top rod where it connects to the z-bar, I just made a spacer to put between the heim and the z-bar. This setup has proven to work great and the adjustability is endless. The long rod has a left hand thread heim on one end to make adjustment as easy as spinning the rod.
 
racerjoe said:
Check out post 197 of my build thread here --> 12:05 Garage- ’70 Duster build

To accommodate the offset for of the top rod where it connects to the z-bar, I just made a spacer to put between the heim and the z-bar. This setup has proven to work great and the adjustability is endless. The long rod has a left hand thread heim on one end to make adjustment as easy as spinning the rod.
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Love this car!

Ill check out the rest of the thread tonight.

Question.

The ends of the factory bar have an oblong hole in them, the heim joint ends are round .

Is it a consideration or did you have to make other linkage mods to use the heims?

Thanks for the response BTW !!



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Super-Cuda said:
Love this car!

Ill check out the rest of the thread tonight.

Question.

The ends of the factory bar have an oblong hole in them, the heim joint ends are round .

Is it a consideration or did you have to make other linkage mods to use the heims?

Thanks for the response BTW !!



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Forgot to mention what I did there. The factory rods connect to a "mushroom" head type stud. They easily knocked out of the z-bar. I think they were just pressed in and not even welded. (aftermarket z-bar). The pedal was another story. If I remember correctly, I had to cut the head off and drill it out. This wasn't fun under the dash. I'd almost recommend taking it out of the car if you plan to do this. Grade 8 fasteners hold the heims to the pedal and z-bar.
 
racerjoe said:
Forgot to mention what I did there. The factory rods connect to a "mushroom" head type stud. They easily knocked out of the z-bar. I think they were just pressed in and not even welded. (aftermarket z-bar). The pedal was another story. If I remember correctly, I had to cut the head off and drill it out. This wasn't fun under the dash. I'd almost recommend taking it out of the car if you plan to do this. Grade 8 fasteners hold the heims to the pedal and z-bar.
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That explains it very well.

I think this is an excellent mod as I have the same setup , centerforce, etc as you.

I will definitely be doing this in the future.

Thanks so much for the tech and advice,

Cheers!!
 
I love everything about this car and build. Well, except the drive, because he's young and a much better driver than I am, for now :lol:
 
Nice to see it coming together.. you've been stalking the swap page long enough :lol:
 
Dantra said:
Nice to see it coming together.. you've been stalking the swap page long enough :lol:
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Yep. Finally going to be one of the cool kids.

I'm hoping to have the 408 out by tomorrow night. After that I just need to trim the frame rail pinch weld, swap the trans over, and it's going in!
 
racerjoe said:
Yep. Finally going to be one of the cool kids.

I'm hoping to have the 408 out by tomorrow night. After that I just need to trim the frame rail pinch weld, swap the trans over, and it's going in!
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I'm sure you're aware of the fitment with the long tubes and the proportioning valve..

what's your plan for fuel delivery?
 
Dantra said:
I'm sure you're aware of the fitment with the long tubes and the proportioning valve..

what's your plan for fuel delivery?
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I don't have a prop valve since I run 4 wheel discs. But the lines do pass near the location of the stock valve.

The car already had port EFI with a MS3X controller. It has an in tank pump in the Tanks Inc tank. I autocross regularly with varying levels of fuel and never once had a fuel starvation problem. I'm currently using the "corvette" filter/regulator and stock reproduction 3/8" steel fuel line. Technically this will work fine, and I may very well get it up and running with this setup. But the plan is to swap over to a return style regulator at some point.
 
I had an early 5.7 in another car that I had similar porting done and decked .030 and ran 6.1 springs. Had to run 6.1 pushrods on the intake side.. Still have a new set of exhaust floating around. Anyway, it was great combo with a mild cam and a 100 shot
 
Dantra said:
I had an early 5.7 in another car that I had similar porting done and decked .030 and ran 6.1 springs. Had to run 6.1 pushrods on the intake side.. Still have a new set of exhaust floating around. Anyway, it was great combo with a mild cam and a 100 shot
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Personally, I think the only thing wrong with a 5.7 is the cam. It's better than a stock 5.9, but it is similar in that it just kind of falls on it's face at about 5200 rpm. Put a mild cam in it and it no longer feels like a truck motor. That's why mine is getting a 6.4 M6 cam.
 
DionR said:
Personally, I think the only thing wrong with a 5.7 is the cam. It's better than a stock 5.9, but it is similar in that it just kind of falls on it's face at about 5200 rpm. Put a mild cam in it and it no longer feels like a truck motor. That's why mine is getting a 6.4 M6 cam.
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Agreed.. 5.7s are great little motors. I put a 6.4 non mds cam and lifters cam in hoopty with a hellcat oil pump. It's a great no tune option
 
Very cool, looks like it will be a fun build... how bad was the 408 hurt?
 
Dantra said:
Agreed.. 5.7s are great little motors. I put a 6.4 non mds cam and lifters cam in hoopty with a hellcat oil pump. It's a great no tune option
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You are running the cam without a tune? I've seen good numbers with that cam but it was after a tune.

Best part is the price, at one point they were less $100 for a 6.4 M6 cam. I think mine was $212 a year or more ago.
 
Icetech said:
Very cool, looks like it will be a fun build... how bad was the 408 hurt?
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I caught it somewhat early. I haven't spun it over to look at the other side of the cam, but the part I can see is fine. Probably just needs to be polished. Likely just needs a teardown and clean with a new set of lifters.

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racerjoe said:
I caught it somewhat early. I haven't spun it over to look at the other side of the cam, but the part I can see is fine. Probably just needs to be polished. Likely just needs a teardown and clean with a new set of lifters.

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Very nice, doesn't look too bad.... i am hoping to do a 390 or 408 shortblock for next year... need to get **** moving on it's own this year first :)
 
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