V8 swap? Or turbo slant six?

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1971Valiant

1971Valiant

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I've just recently picked up my first car. 1971 Plymouth Valiant, 4 door, 198 slant six, three on the tree. I'm trying to decide whether I should swap the six banger for a v8 (maybe a 318, or B-block) Or if I should turbo the slant six. And since I am only 15, I am on a pretty tight budget. For how much it would cost, would it even be worth it to turbo the slant? Or for the money, should I just swap for a v8? If I go for a v8, should I swap the 3 speed for a 4 speed? I personally like the column shift idea though. But, im just wondering what you guys think. V8? or Turbo slant?


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well this question all depends on how much money you have.

if your really on a budget like most of us then why not drive the car as is and get to know it first. Then down the road maybe a super six set up (they don't cost all that much)

Then even farther down the road maybe a small block swap. A 318/360 can be done very cheap.

You would be surprised what a well tuned slant six can do. There is a good reason Chrysler put them in 100s of thousands of vehicles over the course of 25+ years.
 
Well after some thinking, I've decided to drop the turbo and v8 idea, and build up the six cylinder. Cam, Intake, 4 barrel, shaved head, and a header. And maybe a shot of nitrous!
 
I bought a parts v8 duster for 600 and took everything for my duster (disk brakes, v8, trans, rear) which I probably could have run as is but I'm putting another 1000 into rebuilding the motor. Something to keep in mind is if you want to swap to a v8 at any point look for a v8 car for parts. So you don't have to piece things together, it's all there!
 
To buy a 4bbl/intake/cam/headers/all of the supporting mods you have to do to the slant might be as much as a budget v8 swap unless you find these parts used and for a good deal but even then it will not be cheap.
 
Dustert73 said:
To buy a 4bbl/intake/cam/headers/all of the supporting mods you have to do to the slant might be as much as a budget v8 swap unless you find these parts used and for a good deal but even then it will not be cheap.
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Xs2 some of that slant six 4 bbl. stuff is way more than a v8 build which is why I suggest a super six setup which is a 2 bbl. and a factory part so its not all that expensive and makes a huge difference.
 
1971Valiant said:
Well after some thinking, I've decided to drop the turbo and v8 idea, and build up the six cylinder. Cam, Intake, 4 barrel, shaved head, and a header. And maybe a shot of nitrous!
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Nothing wrong with the /6, built right,($$$) it would be cool in that more door sleeper.

Might get to surprise a few people.
 
Look at your budget, be realistic, and don't get in deep enough that you resent the car and don't drive it. My first mopar was purchased at 16 (67 valiant) and I got way too deep for my budget and know how, so I got rid of the car. It was 100% drivable when I got it but I just had to have more. I think about how many years have passed since then and how AWESOME my car could be if I kept it and drove it, fixing it up a little every year.
 
RaniDart70 said:
Xs2 some of that slant six 4 bbl. stuff is way more than a v8 build which is why I suggest a super six setup which is a 2 bbl. and a factory part so its not all that expensive and makes a huge difference.
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Anymore, I'd say the 4bbl would be cheaper IMO. Super six stuff is getting outrageous lately. If he can find a super six cheap, sure. but don't pay more than 2-250 for a COMPLETE super six setup (Make sure it includes the kickdown! If you can fabricate, a cable kickdown from the magnum/4.0 engines can be made work)

Also, keep in mind, slants are pretty limited, not only on parts but on power. If you want BIG (250+) power gains, I'd skip straight to looking into a budget v8 swap. Or you may just be a little slanted like the rest us...
 
Buff out that paint, detail it from front to rear, fix the little things it might need and DRIVE IT. Won't cost you a lot of money, but the results will show big time. You're only 15 (Oh to be 15 again), enjoy the car for a while before you decide what direction you want to take it.
 
PA isn't too far from MI, I have a 225 you can come pull out of my duster to make room for a 360
 
I got a '75 Valiant that's the same color and same lack of options. Makes me wonder if they're fire chief's cars or something....
 
I think you should worry about horsepower in a couple of years when you can throw a few grand into a new engine. Or just do the 2 barrel swap to pick up a few horsepower and then spend money on things like the suspension or maybe even the brakes. As nice as it is to be able to go fast, it's also nice to be able to go around corners and stop on a dime. if you have a lead foot then you're probably better off with a slant that's underpowered because you'll break less things and get less tickets.
 
This is just my opinion but work on the safety things first before thinking about power. When I first got my Dart all the bushings were worn out, the brakes were crap, and my engine was definitely underpowered (a 273 with low compression in one cylinder).

I didn't care and drove it whenever I could. Anyways, one night I tried to put it in park on a sharply inclinded driveway and I missed and hit Reverse (it was dark). Car rolled back, I slammed on the brakes but they no worky. I hit a tree at 5 mph. I cracked the paint, scuffed some trim, and dented the tree. I drove like a grandma on my way home and on the last hill to get to my house, my brakes didn't work either and I had to take a turn at the bottom of the hill at 30 mph with 205/75/14 tires. Not a fun night...

Since then I fixed it up mildly, redoing the brakes and changing the shocks. I still wasn't happy with the stopping and handling performance so I scrapped all that. I'm almost done installing a Hotchkis TVS, 4 wheel disc brakes, and an 8 3/4 I built and know is reliable. All that has been done and the lowly 273 is still in there till I can find a viable replacement.

My point is, before you invest in fun, invest in safety. You don't need to go all out like I did.

And if I had to choose, I would have kept the slant six and slowly purchase the parts to turbo it. No need to build it up.
 
1/2 the price to build up a 318 than a slant, even with a core motor and trans. 318 headers, 119 bucks new..slant headers 300. Good 318 4 intake, 70 bucks..clifford intake..300. Camshafts...about half price. If you like to fabricate stuff, turbo it, otherwise just change the rear out to a 3.31 or something mid 3's.and replace the 1 7/8 headpipe to a super six 2.5 incher and itll be a whole new car driving.
 
Don't waste time with the 198, pull it and sell the connecting rods out of it. Save your money up and put a good used small block in it, you'll be happier in the long run. A hopped up slant six puts out about as much hp as a worn out 318 2bbl running on 7 cylinders.
 
A 318 can be had pretty cheap, sometimes even free; Thats how I got mine. Drive the six cylinder around for a while and save up cash for a 318 gasket kit, timing set, and a carb rebuild kit. Any 318 thats cheap, or again free, is going to need it.

You will need a transmission bell housing for the V8, the bolt patterns are different; you will also need either a V8 K member or an adapter kit, because those are different too. When I picked up my K member, it was cheaper than the adapter kit. I don't know what it is in your area, but look around at wrecking yards for parts.

There is a lot involved in a V8 swap, but it can be a lot better for the money, considering the equipment for LA motors can be found cheaper than for the sixes.
 
I recently did a small block build and swap in my Dart this past summer. The parts list went something like this:

Running 318 2bbl- $300
Gasket set- $60
Cam & lifters- $200
Eddy carb- $150
Performer intake- $150
Rings & bearings- $150ish
Valve springs- $60
flywheel- $80
Bellhousing- $100
Bearing for input shaft- $15
Vat block- $50
Electric fan and aluminum radiator- $300
Schumacher mounts- $175
Headers- $200
Electric cutouts- $450 (gotta have some fun right?)
Mufflers- $140 total ($70 each)
Exhaust shop- $300 (bend and weld pipe, add H pipe, weld in cutout Y pipes, hangars, etc)
Power steering hose- $75 (had to have one made since NOBODY had the one I needed)
Fluids and misc stuff- bout $100
Paint & body work materials for engine bay- $100
Mini starter- $30 from a U-Pull-It

I just did a simple re-ring and didn't bore my cylinders or rebuild my heads. Re used a bunch of stock parts such as rods, pistons, crank, just cleaned em up and re installed them. I'm sure I'm forgetting some stuff and I didn't take the absolute cheapest route either. It can be done for cheaper but I'm happy with the way it turned out. I opted to keep my manual trans and 8 1/4 rear which saved a lot of money. Didn't have to get a new driveshaft or anything like that. Wiring was easy to figger out. Doing all this on the budget of a college freshman wasn't the easiest thing to do and it took me about a year to get all the parts bought. If you want a lot more power don't even bother with the slant. But if you go to a v8 there's a LOT to think about. I'm sure my list is different from a lot of people's but this is what all it took to get my Dart running with a small block.
 
V8 swap for simplicity, turbo slant for coolness.
 
After some thinking, I've decided to keep the 198 for now. And do a very mild build. Intake, header, cam kit, shaved head, and a 4 bbl. But I already have a holley carb, just needs to be rebuilt. And while im having some fun with the slant, im going to be saving up for a 383, or 440, 4 speed swap. But that won' t be for awhile. Thanks for you're input guys! Since I am pretty young, I don't know a whole lot, so if I say something stupid, or something that doesn't make sense, don't make fun of me, haha. I've got a lot to learn.
 
1971Valiant said:
Since I am pretty young, I don't know a whole lot, so if I say something stupid, or something that doesn't make sense, don't make fun of me, haha. I've got a lot to learn.
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Thats what this board is for... Oh you mean you you want to learn something? You can use it for that too...:)
 
[QUOTE="Since I am pretty young, I don't know a whole lot, so if I say something stupid, or something that doesn't make sense, don't make fun of me, haha. I've got a lot to learn.[/QUOTE]
Young, old, and all ages between, the one thing you can guarantee is we all say a lot of stupid things, what separates the many from the few is learning from that
 
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