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Hello,

Fist off, please forgive my ignorance about the Poly engine. Up until a few days ago, I had never heard of such a thing. But I've been doing some research and still don't know much at all. So I'm hoping I can gain some knowledge here.

As I approach retirement, I'm selling off most of my toys and with a hunk of cash in my pocket, I told myself no more projects..... That lasted a week and then this came up on craigslist.

The engine runs as nice and smooth as any new engine out there. It really is amazing to see!

It's a 1958 jeep CJ5 with what I understand to be a Poly 318. This is based off the intake manifold casting # 2206383. The entire drivetrain is covered in 1/2" of grime so that's all I can see for now, until I can clean it off.
I believe the engine, trans and T-case came out of a truck, since there are no adopters to mate any of the components together. Under-carriage is thick with goop and can't see anything till it's cleaned off.

It's a 3 speed manual, with a shift pattern of left forward reverse, left rear first, right forward second, right rear third. Transfer case has the dual shifters. Left shifter forward out, rear in. Right shifter H, N, L.

There seem to be two sets of casing numbers on the left front of the block, just below the head.
One set is HA182201. other is, I think S318-112515.I guess that means it is a 318? What else?
And what transmission and transfer case do I have.
I can't seem to be able to load any pictures. It tells me "file too large".
Thanks.

And looks like the "HA" number is stamped over the "S-318". If that means anything?

i had a 57 cj have a 57 fc now
thinking the trans,t-case are oe
never heard of someone stuffing a polly in a jeep
but use what you got

There's some kind of driveshaft E-brake on the back of the T-case. That's why I think it's not original CJ. Not that I know this for sure. Would a Jeep trany and T-case bolt to a 318?

Read this, then post pics:
viewtopic.php?f=15&t=23632

Poly 318 were used until about 67-68 I think Canada trucks were last to have them.
Twin stick transfer cases were used by Dodge through 68. Those typically had the parking brake on the rear output.
I suspect someone stuck the whole combo from a W series truck into your jeep.

Bucky

Yes, I agree. This thing has the entire drivetrain from a truck.
Still can't load pictures. I'll try to load a screen shot of what error message I keep getting........
OK, why did the screen shot load and not the pictures

712edf wrote: ↑

Thu Jun 22, 2023 12:27 pm

Poly 318 were used until about 67-68 I think Canada trucks were last to have them.
Twin stick transfer cases were used by Dodge through 68. Those typically had the parking brake on the rear output.
I suspect someone stuck the whole combo from a W series truck into your jeep.

Bucky

As I understand it, the 318 was around from about 1965 to 1975, approximately.
Are you saying this engine was used in trucks only up to 67-68?
That would narrow it down quite a bit.

My understanding is the only twin stick transfer case that was available at the time from factory is the Dana 18. Is this correct?
Was the Dana 18 available in trucks?
Then what transmission is it likely to be?

Thanks.

Ifster wrote: ↑

Thu Jun 22, 2023 8:43 pm

712edf wrote: ↑

Thu Jun 22, 2023 12:27 pm

Poly 318 were used until about 67-68 I think Canada trucks were last to have them.
Twin stick transfer cases were used by Dodge through 68. Those typically had the parking brake on the rear output.
I suspect someone stuck the whole combo from a W series truck into your jeep.

Bucky

As I understand it, the 318 was around from about 1965 to 1975, approximately.
Are you saying this engine was used in trucks only up to 67-68?
That would narrow it down quite a bit.

My understanding is the only twin stick transfer case that was available at the time from factory is the Dana 18. Is this correct?
Was the Dana 18 available in trucks?
Then what transmission is it likely to be?

Thanks.

NP 201 is the twin stick transfer case used in Dodge trucks until 69, when it changed to the NP 205.
Likely has the NP 420 tranny, but maybe if its a mid 60's swap it would be a NP 435. Is the cover aluminum or cast iron?
The poly 318 was used from the 50's up thru 66/67 in the trucks, with a few used later in 400 and larger trucks. There is more than one iteration of the poly 318, changing around 63/64.

Ifster wrote: ↑

Thu Jun 22, 2023 8:24 pm

Yes, I agree. This thing has the entire drivetrain from a truck.
Still can't load pictures. I'll try to load a screen shot of what error message I keep getting........
OK, why did the screen shot load and not the pictures

Screenshot (27).png

The screenshot file was small enough to load. I gave you a link above to a lengthy help thread on how to post pics and what you are doing wrong. GO READ IT!

Ifster wrote: ↑

Thu Jun 22, 2023 8:43 pm

As I understand it, the 318 was around from about 1965 to 1975, approximately.
Are you saying this engine was used in trucks only up to 67-68?
That would narrow it down quite a bit.

My understanding is the only twin stick transfer case that was available at the time from factory is the Dana 18. Is this correct?
Was the Dana 18 available in trucks?
Then what transmission is it likely to be?

Thanks.

I think I got you confused a tad. The Poly or 318A engine was available from the mid 1950s until 1966 in cars/trucks, 67 in Canadian trucks. I may be off by one year. But anyways by 1967 in cars & 1968/69 in trucks it was replaced by the 318LA engine, which eventually evolved into the 5.2 Magnum.

Your engine should be from 1957-1967 roughly.

Most dual range transfer cases in the 1950s & 1960 were twin stick. Dodge used NP200 (rear output is NOT in center of vehicle, nor is rear differential) & the NP201. The last year for the NP201 in light duty pick-ups was 1968. I suspect this is what you have.

I think the Dana 18 was used in Jeep or Ford, not Dodge.

Is your manual transmission 3 speed? I no longer have any books pertaining to pre 1968 but I think it might be an A250. Mopar had 2 or 3 different 3 speeds back then. The only 3 speed manual Dodge I ever owned was in a 75 B100 van.

Reread PwrWgnDrvr's posts & his link.

Bucky

Didn’t the earlier poly have a third bolt near the middle of the valve cover also?

BigBlockTrucks wrote: ↑

Fri Jun 23, 2023 12:47 pm

Didn’t the earlier poly have a third bolt near the middle of the valve cover also?

I had an earlier one in a 63. It had the usual 2 bolts on the valve cover. The big difference was a longer crank and block with the flywheel attached with thru bolts, the nut between the crank flange and block (behind the flywheel). PURE HELL to get apart. I slammed that *#%^ into the scrap load! (and the bell doesn't come off until the flywheel is off!)

Ok, I saved a pic as 20% of original, so this is a test of how it'll show. Please bear with me. I know there's a lot I can learn here.
That worked. This is a shot of the block stamp, just below the left head. There are two sets of numbers. What do they mean, and why two sets?
Thanks

712edf wrote: ↑

Fri Jun 23, 2023 11:51 am

Ifster wrote: ↑

Thu Jun 22, 2023 8:43 pm

As I understand it, the 318 was around from about 1965 to 1975, approximately.
Are you saying this engine was used in trucks only up to 67-68?
That would narrow it down quite a bit.

My understanding is the only twin stick transfer case that was available at the time from factory is the Dana 18. Is this correct?
Was the Dana 18 available in trucks?
Then what transmission is it likely to be?

Thanks.

I think I got you confused a tad. The Poly or 318A engine was available from the mid 1950s until 1966 in cars/trucks, 67 in Canadian trucks. I may be off by one year. But anyways by 1967 in cars & 1968/69 in trucks it was replaced by the 318LA engine, which eventually evolved into the 5.2 Magnum.

Your engine should be from 1957-1967 roughly.

Most dual range transfer cases in the 1950s & 1960 were twin stick. Dodge used NP200 (rear output is NOT in center of vehicle, nor is rear differential) & the NP201. The last year for the NP201 in light duty pick-ups was 1968. I suspect this is what you have.

I think the Dana 18 was used in Jeep or Ford, not Dodge.

Is your manual transmission 3 speed? I no longer have any books pertaining to pre 1968 but I think it might be an A250. Mopar had 2 or 3 different 3 speeds back then. The only 3 speed manual Dodge I ever owned was in a 75 B100 van.

Reread PwrWgnDrvr's posts & his link.

Bucky

It is a 3 speed. The dual range, twin stick transfer case rear and front output is offset to right.
Thanks.

S-318 comes up as 1962

Bucky

712edf wrote: ↑

Fri Jun 23, 2023 9:47 pm

S-318 comes up as 1962

Bucky

Great, I need to dig into the trany and T-case some more next.
Thanks.

Can you tell what color the block is?

Bucky

BigBlockTrucks wrote: ↑

Fri Jun 23, 2023 12:47 pm

Didn’t the earlier poly have a third bolt near the middle of the valve cover also?

yes some did.

Bucky

Ok,
Just practicing adding images mostly.
But here a shot of the rear of the T-case