318 Poly Stroke Rebuild or Not

Does anyone on this board have any experience doing a rebuild on a 318 poly using a stroker kit? Am considering my options for my 65 Belvedere wagon. I could go the big block route but was considering my options.

Thanks,

I think you would be far better off building a stroker LA 360 motor for you car than a early poly 318 motor
It will bolt in and hook up to your existing tranny, the only part that won't work is the drivers side stamp steel engine mount, the 340 and 360 are wider on the mounting ears on the block than the 273 and 318 are.
I've seen guys use washers as spacer on their 318 cars, I wouldn't do that but I would use some thick wall tubing as the spacer needed

Build the Poly. It's essentially the same block as the LA (with subtle differences) and heads with a valve layout that are much better than an LA. Sure the Poly weighs more, pistons may cost a little more depending on what you want to do for your build and intake manifold options are limited. There are a number of stroker options based on what you're after. Contact Bruce Toth on the east coast or Gary Pavlovich on the west coast for options and parts.

My new poly isn't stroked but I'll be in the neighborhood of 475 HP, running a TKO600 in my 65 Dodge SNB pickup. Sure, that isn't huge by today's standards but respectable for what it is.

I think it comes down to cost.
a 4bbl intake for a poly is pretty expensive right now.
it is almost as much as a junkyard 5.9 all on its own.
add the stroker kit and you are spending a pretty penny to make it run fast.
I think dollar for dollar you would get more out of a newer block, but if originality look is more important, then that is your call.

Talk to member Polyspheric, if he doesn't chime in...

I like the idea of a 400" Poly myself, especially if the goal is a stock-appearing early B that runs harder than people expect.
Power-for-dollar it's probably not as "good" as other options, but it's different and cool.
My understanding is the Poly heads will be the limiting factor (flow),

Dude, how can you imagine a stock stroke Poly 318 motor making over 300 HP, let alone 400
I've own and driven several early poly motor powered cars including my first Dodge, a 1959 Coronet 2 door hardtop with the one year only 326 C.I. two barrel single exhaust 235 HP rated motor. I traded that intake and carb to a friend who parents had a 318 powered 1959 Plymouth wagon sitting in their driveway collecting dust with a 4 barrel intake and carb, I put dual exhaust on it later but it was still not very powerful
My first Chrysler 331 C.I. Firepower Hemi would eat its lunch in a much heavier car That stock 1955 motor was factory rated at 250 HP
My last 392 C.I. powered 1957 300 C car was rated at either 350 or maybe it was rated at 360 HP in 1957 with the small Carter WCFB,CRS now. The 1958 300 motors with the larger AFB was rated at 375 HP, I think now. I'm not sure about the fuel injected 1958 300 D motors on their factory power rating

I have a 390 Poly. I had Gary Pavlovich build the engine using his Stage IV specs. The heads have 2.02 intakes and larger exhausts as well. Just port matching on the heads to a Weiand 2x4 manifold. The motor made close to 425hp on the dyno.

Sounds like a happy or "high" dyno to me

"Dude" there's no "imagining". The 59' dual-four poly 318 was 290 H.P. with just a camshaft and induction change over the normal poly so getting 300 to 350 is nothing. Without going into everything on mine, it's stock stroke with the usual block and head work but with a small twin-screw supercharger and W/M injection. I never said I had a stock intake set up.

390 HP is not any where near 475 HP, with a stock stroke motor. Stroking it and raising the compression may add another 40 to 60 HP, depending on the cam and peak HP RPM. Me thinks those motor where rated at 290 HP, not 390 HP
On your deal adding a supercharger with water and methanol injection may help you blow the stock bottom end out of it
The poly heads, no matter which brand that Mopar installed them on, where designed for low power and low production costs, not making power above 4000 RPM
I would like to see the manual you got that 390 HP numbers from
The 1957 and 1958 392 dual quad solid lifter 300 letter Hemi motors made less than 380 HP
How and why would Mopar make the 318 motor your talking about have more power in a lot cheaper car?
The 1958 Dodge D500 cars made for NASCAR racing had 354 C.I. Chrysler dual quad Hemi motors in them, check the HP rating on them

We need to set aside factory HP ratings vs dyno ratings, as the factory #s were without accessories, optimized, and influenced by marketing.
Obviously, an ACCURATE dyno tells the real tale, but most of us have seen "happy" dyno #s.
The issue, I suspect, is if a stroked Poly will have the torque to move an early B wagon along on the street while being cost-effective.
Max cost-effectiveness is probably a later 360/5.9, maybe even an EFI deal.
Like I said, depends on how stock-appearing the OP wants.
My stock, tired Polys moved my '63 & '64 stick wagons along pretty well.
Neither (obviously) was at all fast, but pretty adequate, and they were both tired, as in mildly smokin' tired, when I got them.
IIRC, Polyspheric's book had a 400-ish HP stroker recipe, but I'm assuming the OP just wants a street cruiser (torque).

I'll throw this out there: look how hard Dizuster's '62 Savoy runs with a simple turbo 360 recipe...

If you are on Facebook, perhaps this will have interest to you. Am sure the builder has a lot into it- and seems that he must now move this along:

https://www.facebook.com/marketplace/item/269556450712514/

To build an odd engine is aactually very very cool. If your on a beans and rice budget its best to stay mainstream- 318/360. But many of us are at the age where we have some money and want it done the way we could not afford in our younger years. I say build the Poly. And build it with the dual quad manifold and the stroker kit. Im a die hard mopar guy but a 354/392 Hemi or restored Polysphere makes me stop and investigate every time. (Along with the 409 chevy and Y block Ford)

https://www.facebook.com/groups/542278482490634
318 Poly Facebook group. Home of more 400+HP polys than I can count.

You need to check out Toth Performance. He is having a bunch of performance parts made for the poly engines.

I'm wondering what motor was used to make those dyno pulls for that dyno sheet,
I will bet money it wasn't a 318 C.I. Mopar Poly motor
I've dyno a bunch of different brand, sizes and types of motor. I've own a bunch of Mopar cars with different type and sizes of motors in them, I know what 440 HP feels like on the street and at the tracks.
Never believe what you hear and half of what you see is a old adage that I have found to be true in many instances
If it doesn't make since there is usually a reason for that

I will say again. Different is cool. If a bad ask street strip terror is not the goal- or if the budget is not Uncle Tonys Garage level (really REALLY low) a poly 318 is awesome especially with the period correct (and only option available) Weiand dual quad intake.

As the owner of a 396 Poly in a 65 D100 I can tell you it wouldn't be hard for Bruce Toth's other parts to be better than his gen 1 Hemi to poly 318 header adapters,and don't buy pistons from RaceTec.