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318 Poly to 402 Stroker

Mopar Muscle
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318 Poly to 402 Stroker

Batosai Batosai
New User | Posts: 2 | Joined: 09/03
Posted: 09/28/03
12:58 PM

Hi, I'm attempting to build a 402 Stroker out of a '64 318 wide Block with poly heads for my '72 Dodge Dart Swinger.  The only problem is the newest information I have been able to find is 2001.  I had heard that MOPAR MUSCLE put out an article about this conversion in OCTOBER 2001, if anyone has that and could maybe email me a scanned copy or could just give me help on finding parts, what I need to do, etc would be VERY apprecatied.

Thanks for your time, when I get her done I'll post pictures and tech info.

Jay Beebout

(Any replies or help please email me at


goatheat goatheat
Enthusiast | Posts: 325 | Joined: 08/03
Posted: 09/29/03
01:17 PM

did you check with M.M. for back issues? i dont know how far back they go but they have the one you need. also i have been told that some hemi heads will work on the poly v's.  

slohanjames slohanjames
New User | Posts: 8 | Joined: 12/07
Posted: 12/01/07
09:11 PM

Yeah why screw with the poly heads, Hot heads makes the correct hemi heads for it and it will definatly run then.  

Dukeboy Dukeboy
New User | Posts: 12 | Joined: 11/07
Posted: 12/02/07
02:34 AM

Unless your just tryin' to be different, you could build a 408 out of a later model "LA" style motor and will be ALOT lighter...This engine that MM built I'm guessing has around over $5000 in it for 400 H.P.

I could get that outta a 340 with a little nitrous...
For WAYYY less money...  
"You know somethin' Pepper, You can't polish a turd" Will Darnell, Christine...

schurbeng schurbeng
New User | Posts: 36 | Joined: 11/07
Posted: 12/02/07
08:40 AM

It sounds kind of crazy to build a 318 polly but thats why I like the idea. You might find that that old block would make it .090 over. A quick ultrasonic check and you would know. I know thats cheating but a simple 400 inch kit would then work. I always wondered about the potential of these heads. If you do it have fun and good luck I would like to see the results.  

drmopar drmopar
Guru | Posts: 1445 | Joined: 02/08
Posted: 02/27/08
12:52 AM

I read the artile for the 318 poly stroker. The biggest problem you will have is getting speed parts, in fact headers were not available until recently and your only choice is TTI's, if they will even fit in an A body with a poly.
Aluminum intake, good luck finding one.
The bottom line for less money an L.A. or Magnum motor is lighter, bolts right in and everyone has a ton of proven parts for these later motors.
Resale value, there are not to many people who would want the headaces of a poly motor in an A body car.  
Reconsider, there is an easier way.

Dr. Mopar  

User | Posts: 148 | Joined: 02/08
Posted: 02/29/08
05:14 PM

i have a 318 poly im parting out, has steel crank ,and a 4 barrel intake if interested. funny thing is the old poly 318 made more hp than any other wide heh, la smallblock ever built from the factory but I personally wouldnt put the effort into it.Im not 100% positive but I dont think you can use the baby hemi head on the poly 318.I will say I think im 99.9% positive it wont happen though. Confused  

User | Posts: 148 | Joined: 02/08
Posted: 02/29/08
05:17 PM

the 318 poly head sux  

stephen83 stephen83
New User | Posts: 1 | Joined: 03/08
Posted: 03/16/08
12:12 PM

just turned a 318 poly into a 349 ci. never new any made a 402 stroker out of a poly.  

428RR 428RR
New User | Posts: 6 | Joined: 03/08
Posted: 03/20/08
05:18 AM

Yea get a LA 360 stroke it out and forget about the 318 poly.race part are so hard to find.  

Abomination Abomination
New User | Posts: 12 | Joined: 08/08
Posted: 08/03/08
03:13 PM

If you're still parting it out, hit us up at the Poly boards!

You'll find the best vendor list in the world at the Polyspherical Engine association:

At the top of that page you'll find the following links.

The 318 Poly Yahoo Group (which is where we all are, including Gary, who wrote said article):

And the Poly Forum, where we'll all lurkers, and casual posters:,6.0.html

The 318 Poly Sux? Try telling THEM that! What do you think the new "hemi:" is? Laugh

Those factory 4-bbl intakes are rare! Weiand just stopped production of the 7503 after the Holley buyout a few years ago, so there's tons of those floating about. The hemi heads do not swap onto a 318 poly, FYI, but almost the entire bottom end swaps with a normal LA motor!

More info at the sites above...


realfunco realfunco
New User | Posts: 2 | Joined: 06/09
Posted: 06/05/09
12:54 AM

If you still have the intake, I may be interested.  Do you have the carb?       email   801-671-1755   mickey  

realfunco realfunco
New User | Posts: 2 | Joined: 06/09
Posted: 06/05/09
12:57 AM

wanted 318 poly 4 bl, 2x4 bl 3x2 intake manifold   mickey  801-671-1755  

plypoly plypoly
New User | Posts: 1 | Joined: 11/11
Posted: 11/20/11
02:43 AM


jim72 jim72
New User | Posts: 2 | Joined: 09/14
Posted: 09/08/14
03:32 AM

I can't help but laugh at some of these comments Grin ! Poly 318's are far superior to LA series 318's . While the LA 318 is a good little mill It doesn't even come close to the potential of a poly. Sure parts are easier to find with a LA series but those with a little ingenuity can very easily and just as affordably build a poly. The key is building your own intakes and headers etc and actually thinking things out instead of acting like a chevy or honda buffoon and looking for bolt on junk. If thats what you want  MOPAR ain't for you!Currently I own two polys one is a 64 the other a 63. The 64 is stock and dynos at 250hp with a carter bbd the 63 is in the middle of becoming a 402.I also have friends who run polys that have surpassed the 500hp mark with moderate modification.Also if the poly head is such a waste of time then why did chrysler bring back the idea with the new 4.7? I know this is an old thread but hey seeing all the misinformation and snobbery here is the exact thing that is killing the hobby.  

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