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I was looking at a 59 D100 (Could later be converted to 4wd). I was wondering, would a 360 block bolt up to the 59 bell housing? Also, would the 315 flywheel bolt on the 360 crank? Finally, would I have to buy some kind of internally balanced crank/rod/piston kit to make the 315 flywheel work with the 360? Sorry if these are stupid questions, but you could fit what I know about poly engines in a thimble.
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First if this is a 59 it SHOULD have a poly 318 not an earlier 315. A lot of parts do interchange with the poly 318's /360 but none interchange with the 315 engines. Two completely different engines. The poly 318 is a very good engine and can pull as good or better than a 360. There are parts still available for the 318's so don't shy away from that engine. Mopar Norm has headers available for these engine too. The two barrel carb will work fine and has better torque than a Weiand 4 barrel manifold in my opinion. I have one on my Townwagon and I'm considering going back to the two barrel. The easiest way to tell a 315 from a 318 is that the intake manifold on a 315 is raised with a valley cover under it. The poly 318 manifold covers the lifter galley. Hope this helps shed some light. -
Poly 318 vs 360
Does the poly 318 have longer stroke than the 360? If not, what makes it the better engine for a truck?Comment
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The Poly is basically a Hemi with one row of rockers. It has better breathing and exhaust design than the 360LA, in fact a stock Poly will have more torque than a 360 and will get better fuel economy doing it.Originally posted by BenM View Post
Built Polys have exceeded 400 ft. lbs and HP.
The Poly I just built for FrankyB was the only Power Wagon to negotiate the Hollister, Top Truck Challenge Mud Pit.Comment
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Auto Trans Compatiblity
If I got a 318 poly and put it in a truck, would a later trans bell housing from LA small block or a big block bolt on? Or is the poly bell housing pattern different from both?Comment
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The LA to A (Poly) bells will interchange, however to save a lot of work and expense, you must pay attention to flywheel clearance and clutch type.Originally posted by BenM View Post
Some clutches are mechanical, earlier models hydraulic, the donor bell should match what type your truck already has.
Example: The 1969 Dodge had a mechanical clutch, when we installed the built Poly, which had a hydraulic clutch and flywheel, we used the 318 LA mechanical bell AND flywheel because it would mate with the starter. Poly flywheels have the same tooth count as a Hemi and will not work with the LA starter.
Also; LA360's are externally balanced, LA 318's are internally balanced, as is the A318 Poly, so you need to use an LA 318 flywheel and not an LA 360 flywheel.
Big block bells such as BB and RB will not interchange with LA and A bells.Comment
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Poly bells
Don't forget the early 318 (59-60) bell is different than the late 318 (61-66) bell. These are the truck years, the cars are a little different on the cutoff years I think, I can't say for sure.
The difference has caused some people problems and should be checked out.
I have both engines and bells and have been going to get pictures but have not gotten it done yet.
DennisComment
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The difference is the early crankshafts were longer and had a different bolt pattern, exactly the same as the early Hemi's. So the bell is deeper, but the block bolt pattern is the same.Originally posted by iranch View Post
As long as you match bells to the flywheel or flywheel to the bells, with the starter to it's correct flywheel and bell AND the bolt pattern is the same, you are OK.Comment
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318 poly bells
Norm, I beg to differ, the dowel pins are in different places and the bottom two holes are also different. I don't remember about rest of the holes, but I think the radius is smaller also. The 59-60 bell will bolt to the small hemis and their poly equals. The difference between a 58 315 poly bell and a 59 318 poly bell is that the 58 is mechanical on the left hand and the 59 is hydraulic on the right. An early 318 will bolt right up in a 54 to 58 V8 pickup but a later block will not.
There were pictures on the Diamondback Engine forum at one time, but they were in a format I couldn't copy very well. OK I got the pictures and must credit the poster on Diamondback, (probably Jason).
Late block
image001.jpg
Early block
image002.jpg
The ribbing and other details will change by application and are not important, the bolt pattern and dowel pins are all that matters.
But in the end you can't bolt an early block to a late bell even if you change the crank. The hemi adapter used for the 727 trans will work on the early block and should accept the later bell also but would require the long crank.
I personally haven't tried this and but have purchased blocks that people couldn't use because they would not work for them. The Power Giant blocks are the old pattern, the Sweptlines are the new pattern.
DennisComment
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Excellant Information!Comment
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Hi Dennis,Originally posted by iranch View Post
I'm not sure what part you're differing with, did I write that incorrectly and now I can't edit it?...= )
I wasn't meaning to say that you can bolt the old to the new, or vice versa, I was explaining HOW you can bolt a mechanical bell to a hydraulic engine, by changing the flywheels. I think we are now talking about two different things,...however even on the older block styles, while the bolt pattern looks the different, it is actually the same except for the two lower bolt holes.
I can bolt a PW six right up to a hydraulic or mechanical bell, or a 6 bell right up to a Poly, with the exception of those two bolts. However that wasn't what I was referring to....= )
Sorry for any confusion.Comment
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Norm
I was just saying that if you have an early block (59 and 60) you can't safely substitute it for a later block or vice-versa. Without dowel pins and just the top 5 bolts you are asking for problems. The mechanical bell I am referring to was never used on a 318A except on the factory repower kits to replace the 241, 259, 270 and 315 poly engines in the 54-58 trucks. I've never seen a later mechanical bell from the "LA" engine but it should work on the later "A" block with the right flywheel and starter, but the mounts to the transmission cross member are different than the early apps.
It's easier to sub the early block for a Hemi or it's Poly counterparts than it is to use it for a later "A" Poly and even harder to use the late block on any of the early apps.
I understand that to a point we are talking apples and oranges, I was just trying to clarify a little.
It's been 20 years since I had a flat head 6 apart so I don't want to go there at all.
DennisComment
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Got it...I think my meds are stronger than I thought and I misread your first post....= )
My reference to early and late was hydraulic vs, mechanical....= )
The early, early bells with the 1" longer crank do not interchange with the two later types.. . but do interchange with other bells and my doc won't let me stay up long enough to write that much....= )Comment
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Norm
Like we have all been telling you, take it easy and heal up. We are cheering for you.
DennisComment
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