Swapping a Slant 6 for a V8

-
DukeTheDuster

DukeTheDuster

Duke The Duster
Joined
Nov 21, 2018
Messages
21
Reaction score
0
Location
Tennessee
I was wanting to know what engines would be the best to put in my car, it is a 1974 Plymouth Duster 225 /6. I didn’t know if some engines would match the same mount pattern or not so I figured i’d Ask you all since you most likely know a lot more than me! Thanks! Also it’s more of a budget style build/ daily driver
 
DukeTheDuster said:
I was wanting to know what engines would be the best to put in my car, it is a 1974 Plymouth Duster 225 /6. I didn’t know if some engines would match the same mount pattern or not so I figured i’d Ask you all since you most likely know a lot more than me! Thanks! Also it’s more of a budget style build/ daily driver
Click to expand...
Schumacher Creative Services
 
you'll need to buy adapting motor mounts or swap K-frames.

Purpose and intentions for the car will determine the "best" build to drop in.
 
Id go with a good running 5.2 or 5.9 magnum. You be furture ahead in the long run.
 
If your going to do an engine swap go big or go home. 440 is my vote, all the same work to do the swap.
BUT as 318willrun pointed out it really depends on what you are trying to do with the car. If you have never done this before, a stock engine and trans from a donor car would be the safest way to go. You get all the misc bits, driveshaft, mounts, cross members, nuts and bults etc.
 
DukeTheDuster said:
I was wanting to know what engines would be the best to put in my car, it is a 1974 Plymouth Duster 225 /6. I didn’t know if some engines would match the same mount pattern or not so I figured i’d Ask you all since you most likely know a lot more than me! Thanks! Also it’s more of a budget style build/ daily driver
Click to expand...
I installed a 383 using Schumacher engine mounts. I’m still using my stock k member as well, At first I was going to do a 360 swap but figured if I’m going to spend the time and money I might as well do big block.
 
I suggested the running 318 because he wants a budget daily driver. 318's are cheap and easy to find, will work with the 7 1/4 rear (for awhile), won't be too much car for a beginner.
 
451Cuda said:
I suggested the running 318 because he wants a budget daily driver. 318's are cheap and easy to find, will work with the 7 1/4 rear (for awhile), won't be too much car for a beginner.
Click to expand...
Lots of reasons to use a teener. How many bored out 360's run HOT!??? One reason!!
 
Even if your gonna start with a 318, I'd go with the magnum version. Both the 5.2 and 5.9 make around 300 gross hp. They both have good flowing heads and decent cr.

Just going magnum with 4bbl and duals you already have a sweet setup. Add headers and cam if you wish down the road even better. If not got a decent powered with reliability.

Starting with a LA 318 great engine but lack of cr and limited head flow. Even with 4bbl cam and headers would fall short of the stock magnum.

But I'd grab a 5.9 magnum better torque.
 
What about the engine wiring harness? Any difference in the two ? What changes need to be made ?
 
5.9 magnum and keep the efi for a daily driver especially in michigan
so grab the computer and wireing
there are write ups on the internet on this swap
you are not the first one
 
Like stated either conversion mounts or get a V8 K frame. You might want to start looking for a K-frame because Schumacher is having production problems and have been out of stock on most everything they make. I would use the 73-76 frame over the 68-72 frame. Better mounts and you can use the rest of you suspension parts.
I too would do a Magnum over an LA. Many upgrades including roller cam. I have a 400 hp 5.9 in my Dart and am really happy with it. A few million Magnums made so real easy to find.
 
Im old school. Like my LA small blocks. But i do like efi. Have a fitech kit on my Scamp.
 
Nothing wrong with an LA. I've had a lot of them and a few with 200-300K miles on them. The 318 LA is one of the most reliable motors ever made but then so is the 5.2
Easy to do a carb on a Magnum. Many options out there.
 
I purchased a 71 /6 Duster. Probably going with a 360 or 408 with a 727 behind it. EFI for sure. Maybe even an OD transmission. Driver no race car.
 
5.2 w/ 500 tranny from a 90's 2wd Dakota is a good setup. Or a 5.9 w/ 518 tranny from a 90's 2wd Ram.
 
DukeTheDuster said:
I was wanting to know what engines would be the best to put in my car, it is a 1974 Plymouth Duster 225 /6. I didn’t know if some engines would match the same mount pattern or not so I figured i’d Ask you all since you most likely know a lot more than me! Thanks! Also it’s more of a budget style build/ daily driver
Click to expand...
What's wrong with the slant six.

If it is bad you could just replace it or rebuild it. 225s are great engines, I have been daily driving a slant six for years now.
 
I have seen a lot of people give up on slants because they don't realize you can't tune up a slant like a v8. In order to really really get a slant to run, you need to temporarily forget everything you know about v8s because it's not a v8, and tune it like the six it is.
 
So does Warren Buffett
Machining quality is better on the Magnums and availability of virgin cores, roller ready, better heads- lots of reasons unless a matching number build
 
Nothing really wrong with a/6 I'm just a small block LA motor guy. Plus I have about 4 of them out in the barn now. I've built about 10 or 12 of them over the years.
 
Wyrmrider said:
So does Warren Buffett
Machining quality is better on the Magnums and availability of virgin cores, roller ready, better heads- lots of reasons unless a matching number build
Click to expand...

It may be better in many ways but to me a magnum engine just doesn't look right in an old car. Plus I can make 300 or 400 hp with a LA engine too. Its just a street car.
 
I don't know. Doesn't look so bad in a 72. You can also put LA valve covers on Magnum heads but I like the 10 bolt, don't leak covers.

20190309_104358.jpg
 
You must log in or register to reply here.
-

Back
Top