Not really. All you need to use the late engine is an adapter bushing in the end of the crank, and the later flexplate. I sell the bushing, as do several others.

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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

If you really do want high RPM I'd find a block with good thick cylinder walls, bore it to 3.5" and use a 198 crank (3.64" stroke) and rods. If you do this with a short deck 170 then headers will be a Royal Pain, but it saves weight. If you use a 198/225 block then headers are easier by far, but there is a weight penalty. Do the best head work you can or have Mike Jeffries build you a head and you'll be able to spin it pretty high.

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Joshua

I did read some some stuff about making a stroker 170. sounds like it works but it's a bit of work. That would be pretty cool. none of the 198's had forged cranks right?
Just wondering how much power a forged slant crank vs a cast slant crank can take?

oh excellent, then that's not too bad then

Every slant before mid 1976 has a forged crank. 300 hp cast crank engines have been built and lived fine. 200 hp engines have had their forged crank break.

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Joshua

I never could see the logic of building a 170 block with a 198 crank. It is still the same cubes as a 198 engine, if they are both bored the same. And the 170 block would require much more machine work. Both engines would be the same bore, same stroke, same RPM capability.
PS: All 198 cranks were forged, as were 170's. Only the 225 had the cast crank, in the later years (after 1976)

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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

More work,but definite advantages. Lighter overall weight,lighter recip weight due shorter rods and more compact piston design,reduced Piston speed better for high rpm work due shorter rod ratio.... Is it worth it?? We all have different objectives, I guess you have an engine that feels like a 225 in power output but spins better....the OP has already balked at the extra work involved so I'd say no in this case...but if I had a 170 I'd do it...sounds a fun build.

With a stroker 170 you still need enough cam and port to support high rpm...now that would be the hard part on a slant,it would need a lot of good port work.Personally I see no point of wanting to spin and engine for the sake of it if it's waaaaay beyond its power band,I think the OP should just build a stock 225 for a streeter. Spinning a stock slant to 6000?? Really what's the point? your probably making less power than the thing makes at 3000 and it will go boom one day,I guess a 170 may tolerate it for a bit longer....If you want to see 6000 on the tach set it to 4 cyl so it over reads

Ok then I wont worry about forged or not.

Well, sounds like everyone uses the 225 for making power. Seems logical enough. I'll see if I can find a 198, but might just be easier to grab a 225.
So with intake, headers, bigger carb, cam and some head work 200 whp?

With an expertly prepared cylinder head, enough cam lift and duration and enough compression, yes. The head work will make or break this.

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Joshua

Not true...

I don't believe '67 was the year, I thought it was '65(?).....
Anyhow, the registration snout on the earlier torque convertors was smaller in diameter than the later units, ie, where they fit into the crank.
Ed Yost at Wildcat Auto Wrecking in Sandy, OR (503) 668-7786, sells an a machined adapter ring for $20 that mates an earlier trans to a later engine. Piece of cake!

BTW, the earlier trans has the pump in the rear, as opposed to up front. Because of this, you can actually push (or pull) start the earlier cars with the push button auto transmission.

Mike in FL (formerly OR)

1967 was the last year of the small pilot hole crank.
1965 was the last year for the rear transmission pump.
The adapter bushing works fine for using the 1968 and later engine with an earlier automatic transmission.

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Joshua

so can you use the later convertor with the early trans in a later engine?

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1966 Dart GT
4 spd. OD conversion
8 3/4 - 3.55 SG (Sold)

62 Lancer GT
B Body 8 3/4

Not unless you install the later front pump, clutch drum and input shaft into the eary trans. But you cannot install the late low 1st gear parts in the early trans. It is easier to just use the adapter bushing in the late engine, and the early trans and converter.

_________________
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

Thanks!

_________________
1966 Dart GT
4 spd. OD conversion
8 3/4 - 3.55 SG (Sold)

62 Lancer GT
B Body 8 3/4