Big Block Swap

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7Duster6

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Im needing help;I just took the 318 out of my 1976 duster and I'm looking to stick a 383 in it but i have no clue on and parts or procedures for fitment I'm just wanting to stick in it and drive
 
Just for the sake of argument...

Why hassel a big block swap when you can get as much or more hp with a stroked SB. Or just drop a warmed up 360 in.
 
Welcome to the site.
At the bare minimum, you will need custom engine mounts, a big block transmission, exhaust from the heads down, engine harness wiring modifications, a C-Body oil pan and pickup, and you will have to probably need to shorten the drive shaft.
This isn't an easy or cheap swap unless you have all of the parts to do it and are a fairly decent mechanic.
It would be nice if you were more detailed on what you already have and what you expect from the car.
Pictures would be nice as well.

There are a lot of threads on here about this swap, so I suggest you do some reading as well.

Good luck, and keep us informed on how it turns out.........
 
7Duster6 said:
Im needing help;I just took the 318 out of my 1976 duster and I'm looking to stick a 383 in it but i have no clue on and parts or procedures for fitment I'm just wanting to stick in it and drive
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You can't just "stick it in and drive".
1.) You'll need custom motor mount brackets or mods to the K member. Countless threads on here about this, "Search" is your friend. Not currently in production, but rumor has it they'll be back soon, Schumacher's was recently acquired by another company and they are promising new inventory. We'll see.
2.) The smallblock trans will not fit the 383. Different bolt pattern. You'll have to source a bigblock (passenger car) tranny to go with the 383. If your current smallblock trans is a 727, your driveshaft will still work- if its a 904 you'll need to shorten your current one or have a new one made. You'll also need a 727 slip yoke.
3.) Radiator. You may or may not need a different radiator, check your top & bottom inlet/outlets to make sure they will work with the 383. The inlets/outlets changed sides over the years and between big & small blocks.
4.) Exhaust. Depends largely on if you have power steering, but your 3 main options are: factory A body big block manifolds, TTI and Doug's headers. None are cheap. Some people have used B/C body hipo manifolds, but they require steering column mods and may not work with P/S. And the lead time/availability on these things is horrendous right now.
Reconsider using a small block. Much more straightforward. You need to do a little more research before you just start yanking stuff apart only to find out parts are not available or that things don't fit together the way you thought.
 
Professor Fate said:
3.) Radiator. You may or may not need a different radiator, check your top & bottom inlet/outlets to make sure they will work with the 383. The inlets/outlets changed sides over the years and between big & small blocks.
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they are also different size BB vs SB (IIRC)
 
Did ya not read the thread about the small block cars wooping *** on the big block cars? Guess it depends on what ya want out of the car.

I’ll tell ya the 400 HP 340 in my 72 is perfect the ground pounding corner carving machine I built mine into. You dump the clutch at 3k, it just hooks and goes like stink...
 
Scody21 said:
Did ya not read the thread about the small block cars wooping *** on the big block cars? Guess it depends on what ya want out of the car.

I’ll tell ya the 400 HP 340 in my 72 is perfect the ground pounding corner carving machine I built mine into. You dump the clutch at 3k, it just hooks and goes like stink...
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Have you ever driven a potent big block A body. nothing like it. :D
 
fishmens67 said:
Have you ever driven a potent big block A body. nothing like it. :D
Click to expand...

There only good for a straight line. :lol:

And why, when you can get 1.5 HP per inch out of a 418 SBM (600+hp) running 100 av gas. Is 5 pounds per HP fast enough for ya? Not like I built myself a daily driver... and how much more does a B.B. weight over a SB pushing the nose out the corner?? :poke:
 
Who cares what you prefer this guy wants to put a 383 in his Duster.

The largest radiator for a small block will cool a 383 and a later waterpump housing will be needed to use the sb radiator.

At this time fabrication skills will get that big block installed faster because conversation mounts are hard to come up with. You will need kickdown linkage, carb brackets etc..

Hooker makes fender well headers for the Abody big block swap.

Yes a big block 727 is needed.

And an Abody 727 drive shaft is needed, original or fabricated.

If you can't fabricate yourself you will need to find someone who can.

This is not a weekend swap for a novice.
 
If you're going to go to the trouble, at least go for the biggest big block. The 383 adds weight without really adding much cubes over a 360
 
IMO , if you just want to "stick it in and drive" you are in for more headaches than you think . You have : exhaust issues , cooling issues , oil pan issues , changing trannys , torsion bars , brakes , rear axle . rear springs and you are just getting started . It's not a bad swap but it takes planning . good luck !
 
Mopar motor mount brackets 1963-1986 - auto parts - by owner -...

A start. You can do it. Plan on steady work ie parts ordering/shipping. Have a good idea of theme of the car and stick to it.....deviation costs money. check out how to drop the motor out the bottom. engine bay generally gets the same paint as car color. Make a "sure grip" part of the budget.

GO GOLD!

Oh.......WE WANT PICTURES!!! Current state, after....during....all the info a guy could want on here.
 
66fs said:
I'll take a 383 any day over a 360. Actually any small block over a 360...
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383 with free flowing exhaust and 3.55 or lower gear is a different beast than any stock small block A-body.
Big block swap in an A body is old hat for me, It's really not that much more money if you're starting from scratch and rebuilding a 50 + year old drivetrain.
 
I am in the part collecting phase of pulling the w5 340 stroker and od 4 speed out of the 67 dart and stuffing into 96 dakota.

Planning to stuff a 400 stroker into the dart, but with a t56 trans and eventually dana 60.
Mounting with AR engineering motor plate. I picked up some used tti headers.
I added electric power steering last winter. I have not had the car out since spring of 2020

I sort of built the car 10 years ago with lots of hp in mind. So its basically setup for big block already
 
fishmens67 said:
383 with free flowing exhaust and 3.55 or lower gear is a different beast than any stock small block A-body.
Big block swap in an A body is old hat for me, It's really not that much more money if you're starting from scratch and rebuilding a 50 + year old drivetrain.
Click to expand...

True, no special engine parts needed.
 
jos51700 said:
If you're going to go to the trouble, at least go for the biggest big block. The 383 adds weight without really adding much cubes over a 360
Click to expand...

A 440 is an even more difficult swap because it's taller and wider than a 383. I do agree that there's no replacement for displacement :D

I would recommend to the OP (assuming he doesn't already have the 383) that he find a good 400 block and build a 451 or 470. That's just as easy to fit as a 383, since it has the same external dimensions, and much more powerful. Stroker kits are readily available and don't cost much (if any) more than rebuilding a 383 to stock specs!

I love my 451, although I did it the hard way (400 block, 440 crank turned down to fit, Eagle rods, etc., all acquired over many years)... OP would be really happy with one of those in a Duster!
 
i already have the 383 and the 727 my uncle is intoned school mopars and my cousin is a good mechanic but no one is sure about fitment and compatibility for the swap but I'm just 20 and grew up liking old muscle cars but this is the first car i bought bc my dad has a 68 dart and my uncle has a 71 challenger but thanks for the feedback
 
Scody21 said:
Did ya not read the thread about the small block cars wooping *** on the big block cars? Guess it depends on what ya want out of the car.

I’ll tell ya the 400 HP 340 in my 72 is perfect the ground pounding corner carving machine I built mine into. You dump the clutch at 3k, it just hooks and goes like stink...
Click to expand...
I don’t think I’ve ever seen a Sb kick a bb. Kim
 
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