Well,

I've got a 1973 Duster and I totally roasted the motor. It was a 225 Slant Six with a Single Barrel Carb. I was planning to build it up, so I've already got a Clifford Intake, Edelbrock 4 bbl performer carb and Headers -- but I need advice. I want a fairly good performance setup that won't destroy my 7 1/4 open rear. I've got a 904a Torqueflite that's in good shape.

The question is -- I'm planning to order a rebuilt Slant Six. But should I get a 170, 198 or 225 slant six? I know the shorter stroke Slants tend to perform better under certain circumstances. My Duster is a cruise car -- its got tall 2.73 gearing If I'm not mistaken. It runs a single pipe 2.25 with Flowmaster Super 40 muffler.

I was also planning to get the slant six overbored with a performance camshaft. But what's available? Sorry if I ask a lot of questions.

Since it seems like you cant post anything on theis website without citing it(else the sponsors, ect. dumb you down and just to prove your wrong), this is just an opinion.
I would go for the 225 because it has plenty of tourqe for a street cruiser. I used to want high horsepower but once I read more into it, I figured that high tourqe at low end is perfect for around the city driving.
Escpecially at red lights when theres a Civic next to you...

Nope. Wrong.

The Sponsors

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If it ain't broke, fix it!

as the saying goes, there is no replacement for displacement. i dont think youll want to step down to a 170 or 198 when youve already had a 225. unless you want a revver.

Yes,

My undertanding is that the 170 is better for an all-out race motor in a light car. That way, you can take advantage of the shorter stroke and run the revs up to get some top end HP.

But you don't want to do that, since you are building a driver, and it's a fairly heavy car with tall gears.

With those gears, you might want to stick with the stock (early 70's) camshaft - you'll get good mileage and decent off the line.

k

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1963 Dodge Dart, motor by Doug Dutra, Offenhauser two carb intake, Pertronix, Clifford 6x2, Flowmaster 40's, Erson RV15/295 RDP, head work. Addco anti-sway bar, urethane suspension bushings, KYB's, racing leafs, SSBC discs. Need ZDDP? Get STP.

As previously stated, "there is no substitute for cubic inches", except cubic money. In my opinion, the only reason to use a 170 motor, is if class rules require that displacement, or if you already have one in good condition. I run the 170's because the rules required that, when I raced many years ago, and those are the motors I had on hand. The new motors I am building are 225's. It is actually cheaper to build a 225, then a 170. You can mill the head more, and run a bigger cam, without have to put valve notches in the pistons. You cannot cut the deck on a 170, to increase the CR, but a 225 will allow a .100 cut.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

i think you can go more than .100 off the deck on a 225. when i ordered some parts from the cox brothers last year, they told me they have done over .200 to .250 off deck for different engines, but it pretty much takes off the upper mounting lug for alt ,so you would need custom brackets for the street. the deck is .375 to .500 thick to begin with. ron

I really don't know how much can be removed from the deck of a 225. I just used the .100 figure as an example, to compare to the 170, which can only tolerate a cleanup cut, with out haveing the pistons come out the top of the block.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

ok i need help wiht just trying to rebuild a 225 from a 1972 duster. if anyone can help ust send information to DislexkLBCkid@hotmail.com

Unless you have the time, money and tools needed to rebuild an engine have you tried any of these cheepies/freebies?

-Do a compression test to see where your at to start with. Around 150 +- 10#'s is good
-New cap,rotor,points,condensor,spark plugs
-Flush and replace all fluids; oil,tranny,coolant
-Adjust vaule lash
-Replace old air filter, oil filter, any old cracking hoses.
-Timing
-maybe run a little more psi in your tires...? <-- REFERENCE ONLY DONT' TRY

Before you decide to rebuild your engine try those?

i just did a compression test on my /6 and it was around 130psi. is this bad? no change with oil added? sound like valves?

If you have 130 PSI across all cylinders you are doing fine. The last running slnt six I did a compression chjeck on had pressures varying form 90 to 11 PSI, and it still ran acceptably.

Build a 225, get a cam such as the Comp Cams 264 (don't start, I know some folks hat eComp Cams, I am just using that level of cam as an example), and don't forget to upgrade your exhaust.

Honestly, I think the Clifford and Edelbrock might be too much for your car. If it were me i would track down a Super Six intake (or make your own from a one barrel intake) and run a Carter BBD or a Motorcraft 2100 or Holley 2300 carb. Those 2.73 gears will eed lots of torque down low in the RPM range.

I'm going through the same process - replacing my seized 170. I am going to find a 225 and have it rebuilt at a machine shop I trust. 225's are much more plentiful in the boneyards and the machinist I talked to says the 225 parts are cheaper than the 170. And why not get 55 more cubes if your 170 is hosed? I am just looking for a reliable cruiser, not a high end screamer. A 4.125" stroke engine in a light car has to be pretty satisfying at least up to 4000 rpm.

[quote="Pat Dawson"] the machinist I talked to says the 225 parts are cheaper than the 170. quote]

Not so. The only parts different between the 170 and the 225 are:
1) the block
2) crankshaft
3) con rods
4) pushrods
and most likely, those will be reused on a rebuild. The cost to machine/recondition, the first three items will be the same, regardless of it being a 170 or 225. The cost of any new pushrods, if needed, should also be about the same, 170 or 225.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225