Quick... which way's better (225/273)

[ValiantKevin]

WHAT WOULD YOU DO??

So I bought my 67 Valiant a few weeks ago, she's got a so so tired 170 that smokes and power of a manual wheelchair.
Since buying it I have been pretty set on building a 225 with internal goodies to be paired with a turbo... maybe a ~300hp range build because I want it streetable too.

THEN this lil guy popped up... a 273 small block out of a '68 Satellite. Unknown miles but ran when pulled (like they all say lol) however it is a pretty clean motor, stored in a storage unit with plugs in it and all the open ports taped shut (intake, exhaust, thermostat housing, carb, and even the valve cover breather holes) meaning stored nicely I guess is my point.
Engine is complete oil pan to valve cover, has a cast 2bbl intake on it and a distributor too but no carb.
It ALSO comes with a Holley Street Dominator 4bbl intake that's clean too.

MY INVENTORY ON HAND:
(In car, 170 with a 3 speed floor shift converted)
A rebuilt 4 speed A body A833 transmission
2 Bellhousings:
1 to put the 4 speed behind the S/6
1 to put the 4 speed behind a V8

Valiant already has 11" front disc brakes and a 8.75 (3.23) suregrip rear end.

Besides exhaust and motor mounts (which I see now companies make slant 6 to V8 mounts so I don't have to switch my K member) what else will I need?
Drive shaft the same length? Crossmember different? She already Manual steering and brakes so nothing to worry about there... anything I am missing?

What do y'all think I should do, WHAT WOULD YOU DO?... pull the trigger and go with the 273, build it, maybe turbo it too... or stay with the 6 and WHY?

 

[Murray]

For me= doing the V8, 4sp now will open many options in the future.

 

[318willrun]

I like the sound of the V8 (sorry RRR... lol), so I'd go V8. Then, if you want more motor, you'd be set up for a bigger small block down the road, if you so choose...

 

[rklein383]

V8 all day.

 

[Syleng1]

V-8 and use that /6 as a table or boat anchor or a place for you to plant 6 tomato plants.

 

[abodyjoe]

i prefer the v8

 

[Mopar Sam]

 

[Darter6]

Tho I love me a Slant,dollars and cents you will have a better day in a V8

 

[NC Engine Builder]

V8 every time, cant go wrong

 

[Dana67Dart]

V8 V8 V8 V8 V8

 

[273]

Even a small V8 has more potential than a 6, 16 intake and exhaust valves vs 12, and 12 poor flowing ones at that, far worse than a 273 heads. And if street able is important you at least want similar cid to hp, preferably more cid than hp.

 

[Mtrhead]

I would like to see a 273 built up with a set of trick flow heads a good cam and a lot of goodies maybe a pop-up set of Pistons...in the 90"s The Darn Dart from Rockingham ran 10.90 with 273,Xheads,Trw domes, solid big cam..steep gears

 

[273]

I would like to see a 273 built up with a set of trick flow heads a good cam and a lot of goodies maybe a pop-up set of Pistons...in the 90"s The Darn Dart from Rockingham ran 10.90 with 273,Xheads,Trw domes, solid big cam..steep gears

That would be like a 9,000 rpm engine Even Stock Magnum's heads would be a lot of cylinder head for a 273.

 

[JDMopar]

V8 for sure.....BUT, unless the 273 is dirt cheap I'd find a 318 or a 360 instead. 273's are good motors if you build them to zing way up, but decent pistons aren't cheap, you can't run 2.02 valves unless you notch the top of the bores which makes bigger port heads hard to use. I built a nice 273 a few years ago for my 65 Barracuda and have another one to build (kicking and screaming) because it's the numbers matching motor for our 69 Dart Gt conv.

 

[abdywgn]

273. I had that combo and always thought it was a 318; that is what the PO told me. never doubted it, ran well and was a bunch of fun. as said, once the V* is in, you can always go bigger. replace all the freeze plugs before you drop it in.

 

[65TerrorCuda]

Another 273 vote.

 

[PROSTOCKTOM]

Your friends and family will ride with you if you have a V8. Well on the other hand you might not want them to ride with you.

You can't go wrong with a V8

Tom

 

[RustyRatRod]

Regardless of what the crowd says, it's always easier and more affordable to leave a car with the type engine it came with. That said, 300HP is a tall order for any slant 6 that doesn't have a blower or turbo. I have one on the stand now that MIGHT reach out and touch it, but it has a head that has had 318 valves put in it, it's been ported big time and the rest of the engine is far from stock. Even with all that, I would be very shocked if I got 300HP. But I'm not going for a number. I'm going to have fun. Remember, these cars are light. They don't need a crap load of power to be fun.

 

[Bewy]

Go for a 318, plenty to choose from. With just a mild cam upgrade, you will have a smooth idling engine, with plenty of power, complimented by the Holley intake with an Edel 650 AVS carb.

 

[AJ/FormS]

If you already have the 273, why is this even a question?
But if you don't then, for me,
the obvious choice is /are;
1) a hi-pressure, alloy-headed 360 with a very modest cam. Get the pressure up to say 190, run an A833od with 3.73s for 75=2540 with 27" tires. or
2) if you want to keep the regular A833, then, run a 318/340, but for performance., you'll need more rear gear, with the 318 . or
3) run a stock Magnum, any size with your choice of rear gear.

 

[junkyardhero]

If you already have the 273, why is this even a question?
But if you don't then, for me,
the obvious choice is /are;
1) a hi-pressure, alloy-headed 360 with a very modest cam. Get the pressure up to say 190, run an A833od with 3.73s for 75=2540 with 27" tires. or
2) if you want to keep the regular A833, then, run a 318/340, but for performance., you'll need more rear gear, with the 318 . or
3) run a stock Magnum, any size with your choice of rear gear.

what about a maximum influence 324? or ab HO 273? does that change the calculus on transmission to use?

 

[RustyRatRod]

what about a maximum influence 324? or ab HO 273? does that change the calculus on transmission to use?

Now wait a minute! You're leavin out the sinister slant six.

 

[Oldmanmopar]

K-member. I had the schumacher mounts but I sold the left side. which is the same as 273 318 mount. The right side which would be the one needed is still here somewhere. You can have it if you need it. Just pay the ride .

 

[RustyRatRod]

WHAT WOULD YOU DO??

So I bought my 67 Valiant a few weeks ago, she's got a so so tired 170 that smokes and power of a manual wheelchair.
Since buying it I have been pretty set on building a 225 with internal goodies to be paired with a turbo... maybe a ~300hp range build because I want it streetable too.

THEN this lil guy popped up... a 273 small block out of a '68 Satellite. Unknown miles but ran when pulled (like they all say lol) however it is a pretty clean motor, stored in a storage unit with plugs in it and all the open ports taped shut (intake, exhaust, thermostat housing, carb, and even the valve cover breather holes) meaning stored nicely I guess is my point.
Engine is complete oil pan to valve cover, has a cast 2bbl intake on it and a distributor too but no carb.
It ALSO comes with a Holley Street Dominator 4bbl intake that's clean too.

MY INVENTORY ON HAND:
(In car, 170 with a 3 speed floor shift converted)
A rebuilt 4 speed A body A833 transmission
2 Bellhousings:
1 to put the 4 speed behind the S/6
1 to put the 4 speed behind a V8

Valiant already has 11" front disc brakes and a 8.75 (3.23) suregrip rear end.

Besides exhaust and motor mounts (which I see now companies make slant 6 to V8 mounts so I don't have to switch my K member) what else will I need?
Drive shaft the same length? Crossmember different? She already Manual steering and brakes so nothing to worry about there... anything I am missing?

What do y'all think I should do, WHAT WOULD YOU DO?... pull the trigger and go with the 273, build it, maybe turbo it too... or stay with the 6 and WHY?

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And lest you think a slant six cannot sound good this is mine. It runs as well as it sounds. Granted, they'll never be a V8, but they weren't meant to be.

 

[Darter6]

300HP is a tall order

It is doable, normal aspirated slant six.All that is required is the proper budget.