Hemi heads on a poly?

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TheTecher

TheTecher

Evan the jeeper.
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I have heard that this is possible, is it? I have 318 poly just taking up space in my driveway. Soon I hope to get a model a truck! My plan is to stroke the poly and put hemi heads on it if possible, it would be sick with the push button 727, Im thinkin rat rod!=P~
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Yeah and I heard Kate Beckinsale is coming to my place for a booty call.
 
Some of the poly motors also came as a Hemi - 270, 315, and 354 comes to mind. I don't think the poly 318 ever did and don't think it will convert to a Hemi. If it did, it would require all the internal Hemi stuff as well. You might check over with Gary Pavlovich (poly guru) over at the poly forum on Yahoo.
 
Ok thanks dartman. I knew that it had to be one of the older hemi heads. Maybe Ill just stroke it or leave as is. It runs, I dont see much sense rebuilding it now.
 
there are some parts for the old 318 poly now, jegs offers headers, not cheap though, hughesengines.com sells pistons, and if you look around in enough salvage yards, they did make dual four barrel intakes in the late fifties for the Furys and Belvederes, I believe it was called the Golden Commando then
 
Biggest HP stock small block chrysler was a 318 poly..... Good head design, with some work.
The HEMI has more head bolts, for starters..............
 
racer you must be ahistorian or you lived back then.....my dad had one and older brother raced every kid for miles around ......still rember him coming over the hill and up the drive into the barn and closing the door just in time ....as 57 cop car went by....good info....bonehead
 
From my understanding, talking with alot of the old Hemi guys. The L.a. 318 poly could be changed over, also the 325. Read Tex Smiths book on early Hemi builds. I don't beleave the 354 was ever a poly,its the same block as the 331 and 392. the 240 , 270 were concidered baby Hemis. Another good person to talk with is BoB Walker at Hot Heads. He can tell you pretty much what you need to know. I got everything i needed from him to build my 354 for my Dart.
 
If you check the bolt pattern on the heads, the old style hemi heads can bolt up to the poly block.
 
My understanding is the Windsor Poly which was unique to the Chrysler line would accept the hemi head, whereas the Plymouth Poly would not. Regardless the Poly engines which were dubbed "semi hemi" will, with proper porting put out HP numbers comparable to the hemi.
 
I can put a set of the small Hemi heads on my '56.... It has a 270 (Semi-Hemi) Red Ram Poly in it. I know it's not as easy as just bolting on the heads. By the time I would go through all that I might as well do what I want to.... 440 strocked to 500" with a 5spd behind it. Hey, that cars heavy... I need the torque. lol
 
There are 4 distinct poly engines and 3 distinct early hemi engine families. The Chrysler, (301, 331, 354, 392 displacement, 4.5625" bore spacing), Dodge, (241, 259, 270, 315, 325 displacement, 4.1875 bore spacing Desoto, (276, 291, 330, 341, 345 displacement, 4.3125" bore spacing and the Poly A engine, (277, 301, 303, 318, and 326 displacement, 4.46" bore spacing). For dimension details, check here

http://users.erols.com/srweiss/tablersn.htm

You can switch hemi and poly heads within engine families of the same bore spacing. The poly A engine does not have a hemi head made within its vintage, but it shares bore spacing with the LA engine and the new hemi. I have not tried it, but I have heard you can bolt LA heads to an A block. Not sure about the new hemi heads, but I can't see any advantage to putting these heads on an older A or LA block.
 
Stroke it, port the heads, get a Gary P blue printed rocker assembly, moly rods, Gary P ground cam cam, TTI headers, Dual quad with 500cfm Edelbrocks and pump out 402 HP
 
Not a historian or lived back then, the 80 is the year I was born. Just got a lot of reading material and know quite a few seasoned hot rodders who did run around "back then" and have forgotten more than I'll probably ever know.
 
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