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Author Topic: Gen 3 Hemi  (Read 2550 times)

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Rox86

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Gen 3 Hemi
« on: September 01, 2019, 18:53:18 »

The wife and I are trying to figure out which way we're going to go with our Fifth. Before I hear about a 360 or magnum being cheaper and easier I'll start off with the fact we are in CA. Trust me, if I could I'd already have a 5.9 magnum ready for a swap.
Engine swaps are legal here but two things.
1. Has to be the same year or newer. So 360's or big blocks are out.
2. Has to be from the same smog class. So magnum engines are out. (passenger car vs light duty truck)
The next v8 that any Mopar sedan had is the 5.7 hemi and we've been really tempted by it.
I know there are motor mounts that will adapt it for a F-body engine bay and there's a company that makes a flexplate and starter to use the hemi with the 904 trans. But I've never seen one in an M-body.


Anyone have experience with this swap? Either to help or talk me out of it  :biggrin:  I'm sure the ecu and fuel system will be the hardest challenge. But what else does it take to drop a modern hemi into one of these cars? I know the rear end will have to be beefier and subframe connectors will help a great deal to, but I'm just focusing on actually getting it in the car running and driving for now.


I may add, this is a few years down the road and definitely need time to save up.
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Re: Gen 3 Hemi
« Reply #1 on: September 02, 2019, 01:09:30 »

F, J, and M bodies interchange front and rear suspension components completely. The engine mounts are basically the same for most rear-drive passenger cars from 1973 to 1989. That makes still a mid sump oil pan unlike the front and rear sump pans used by 3G Hemis. Wiring up the ecu et all isn't so bad if you go ahead and get the underhood fuse box and as much wiring as possible from the donor car.

An 8-1/4 would hold up to a 3G Hemi just fine.

So why not swap a 5.9 Magnum, dress it up as a same year cop car motor, and call it good?
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Rox86

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Re: Gen 3 Hemi
« Reply #2 on: September 02, 2019, 06:52:44 »

F, J, and M bodies interchange front and rear suspension components completely. The engine mounts are basically the same for most rear-drive passenger cars from 1973 to 1989. That makes still a mid sump oil pan unlike the front and rear sump pans used by 3G Hemis. Wiring up the ecu et all isn't so bad if you go ahead and get the underhood fuse box and as much wiring as possible from the donor car.

An 8-1/4 would hold up to a 3G Hemi just fine.

So why not swap a 5.9 Magnum, dress it up as a same year cop car motor, and call it good?


If I swap a 5.9 it's going to have to blow the same smog numbers as the stock 5.2. For smog they put the sniffer up the tailpipe and put the car in the Dyno. Where I live specifically too the cops have been known to set up smog check points much like dui check points. With the Hemi the car will be smogged to the hemi standards, not an 1987 318 standards.
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Darth-Car

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Re: Gen 3 Hemi
« Reply #3 on: September 03, 2019, 19:15:25 »

I have a 5.7 HEMI in My Beautiful Bride's 08 Aspen.  I am not thinking that a 904 can handle this monster.  I would want to mate it to a 727.
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Re: Gen 3 Hemi
« Reply #4 on: September 03, 2019, 19:23:28 »

I have a 5.7 HEMI in My Beautiful Bride's 08 Aspen.  I am not thinking that a 904 can handle this monster.  I would want to mate it to a 727.
X2
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Mike

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Re: Gen 3 Hemi
« Reply #5 on: September 04, 2019, 17:44:03 »


If I swap a 5.9 it's going to have to blow the same smog numbers as the stock 5.2. For smog they put the sniffer up the tailpipe and put the car in the Dyno. Where I live specifically too the cops have been known to set up smog check points much like dui check points. With the Hemi the car will be smogged to the hemi standards, not an 1987 318 standards.

My 360 with 4 barrel passes with 318 numbers. The big thing is to have a functioning cat and EGR system.
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Mike

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Re: Gen 3 Hemi
« Reply #6 on: September 04, 2019, 17:45:38 »

X2


X3
I've killed enough 904s with 360. They might be less weight and rob less HP with smaller internals but I'd rather have reliability.
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Re: Gen 3 Hemi
« Reply #7 on: September 04, 2019, 18:11:23 »

I have a 5.7 HEMI in My Beautiful Bride's 08 Aspen.  I am not thinking that a 904 can handle this monster.  I would want to mate it to a 727.
He might as well start looking for a 8 1/4 or 8 3/4 also.
That 7 1/4 is sure to grenade with a Hemi.
« Last Edit: September 04, 2019, 18:11:53 by 80 Lebaron Coupe »
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Re: Gen 3 Hemi
« Reply #8 on: September 04, 2019, 18:15:28 »

My 360 with 4 barrel passes with 318 numbers. The big thing is to have a functioning cat and EGR system.
That's the way to go in my opinion.
Were not saying Magnum. A LA 360 will use several of the external parts you already have on the 318.
FAR LESS money for the can of worms your about to open with a Hemi swap.
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Rox86

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Re: Gen 3 Hemi
« Reply #9 on: September 04, 2019, 19:33:05 »

With all due respect to everyone. A 360 is not a legal swap in California. If it was I'd already be doing it. It may make better smog numbers than a 318 with work but it's not worth getting caught in CA.
With a hemi I can go to a CA smog referee pay my $25 for the inspection and the car is legal. As long as the of equipment on the hemi is still present.
I plan on keeping this car for as long as I can. I don't plan on a hemi swap tomorrow but definitely something I want to do in the future.
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Mike

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Re: Gen 3 Hemi
« Reply #10 on: September 04, 2019, 23:59:35 »

Not being in California but seeing a fair number of swaps going on and different vehicles from there I'd wonder how stringent they really are with the truck thing as people throw 350s and LS1 engines in everything and don't seem to have any problem with licensing and smog.
The plus about 360 is essentially no-one would be the wiser. They are identical to 318 and an inspector would really have to know what they are looking at to figure out there's something going on. The downside is they are worse on gas.
Hemi would be a cool swap for sure. I know the engine mounts are available but I wouldn't think too much about that, if someone can do the other fabrication needed to get it fitting in the car it wouldn't be too big of a deal to fab up their own mounts too.
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Rox86

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Re: Gen 3 Hemi
« Reply #11 on: September 05, 2019, 07:13:43 »

I used to own a '79 El Camino. Chevy is a way different world than Mopar. Everyone and their mother makes speed parts that come with smog certifications. I had a 350 in mine and I could do heads, cam, exhaust, intake, carb and it still be smog legal. Nobody makes smog legal parts for Mopars.


Unlike Mopar, Chevy V8's didn't die in 1989. So there's a lot more engine choices to choose from. Both truck and car. Not to mention everyone makes full crate motors that can be smogged. And everything pre-1975 is completely exempt from smog, so you can do anything you want to it. The law doesn't say the swapped engine has to be from same manufacturer. So I could swap in a LS1 and still get it certified. Heck I go throw a 2jz in the car and can still get it certified. But I'd rather keep it Mopar.  :biggrin:


I throw a 360 and still can't throw speed parts at it cause it'll change the smog numbers. I'd have to run the same carburetor and ignition system. Still have to run all 3 cats.
« Last Edit: September 05, 2019, 07:16:18 by Rox86 »
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Re: Gen 3 Hemi
« Reply #12 on: September 05, 2019, 07:33:41 »

Unlike Mopar, Chevy V8's didn't die in 1989.   
I can see now that your are one of those that will have to learn the hard way.
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Rox86

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Re: Gen 3 Hemi
« Reply #13 on: September 05, 2019, 08:03:57 »

I can see now that your are one of those that will have to learn the hard way.
My mistake, I meant in passenger cars. Chrysler didn't offer a v8 passenger car until the 2006 charger. Again going back to classes of smog in CA.


I know a hemi is the hardest swap out of all the choices. But I was trying to figure out what exactly makes it hard. Wiring? Fabricating? Expensive? Just thought a hemi would be something different in a world of LS-swaps.


I'm okay with the stock 318. I love that motor. If I could just build up the stock 318 to about 250-300 hp I'd be happy. Even just bone stock I'd be happy. But they aren't going to keep making replacemt parts for it forever. After owning a hemi charger, I thought it'd be a fun swap.
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Re: Gen 3 Hemi
« Reply #14 on: September 05, 2019, 12:10:22 »

I'm okay with the stock 318. I love that motor. If I could just build up the stock 318 to about 250-300 hp I'd be happy.
You hit the nail on the head when you said EXPENSIVE on the Hemi swap.
A modified 318 is the way to go for that car.
I highly doubt there will be a shortage of LA motor parts anytime soon.
Build yourself a 318 on a stand in the Garage until you have gathered all the parts needed before you yank the engine. that way you can still drive the car.
There are videos on you tube about the defects of the 5.7 and should be studied before jumping into one. Uncle Tony's Garage is one of them that talks about it.

Machine shop work, 30 over Pistons one paycheck, cam and lifters the next etc. until you have all you need to pull it off.
I have been doing it that way for over 41 years and it hurts less doing it little by little.I myself love the 360 and have several vehicles with them.
If you get a high enough compression pistons you can run 360 heads, preferred the later F.I 308 castings. because using 360 heads on a 318 will drop the compression one point.If they are a 9.5.1 it will drop it to 8.5.1 with the 360 heads. which is a good street able pump gas compression.
Don't go over a 270 for a cam or you will need a stall torque convertor for the trans.300 horse is not hard to achieve done right.
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