Quick questions Magnum Heads - Is there a difference between 318 & 360 magnum heads?

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greymouser7

greymouser7

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Some of the people that list them say 318/360.

-This makes me think that it's a 318 head if there is a difference.

Is there a difference with the engine quest aftermarket heads?

92-01 are the years for Magnums right?

thank you thank you
 
Nope, same valve and port size. Magnums were cast at two different foundries
so there may be slight differences between heads but the stock heads are the same. tmm
 
The 360 didn't start until 93 I believe with the 318 being made a year earlier. But 92 sounds right for the first 318 Magnum. If you have the heads off then have them checked for cracks, very few factory castings didn't crack.
 
The magnun 5.2 came out in 92, the magnum 5.9 came out in 93.
 
The Magnums are great for mild/moderate builds. They have a big pushrod pinch though, so flow can be limited on higher HP builds. All in all, IMO, they are a step up from bone stock LA castings, because they offer bigger valves, smaller chambers and higher ratio rockers. I'm a BIG proponent of the shaft mount rocker system, so that's a statement coming from me. Another advantage to me is, the magnum stuff.....like the timing cover and water pump will accept the serpentine belt system. I'm putting it on my 318. I don't wanna spend a lotta time huntin up v belt pulleys tryin to find the right ones.

Lastly....if you find some that are NOT cracked, unless you do something stupid like overheat the hell outta them, they probably will not crack. Also, cracked ones are not necessarily junk. If the crack is only in the valve seat, and does not extend into the chamber, or in between the valve seats, replacing the seats will repair them. I wouldn't trust too many folks with cast iron repairs. Dover Cylinder Head in Atlanta is one I would trust, though.

Oh and the port sizes on the Magnums are same as the LA 340/360. That's even yet another benefit.....for upgrading a teen anyway.
 
StrokerScamp said:
The Magnums are great for mild/moderate builds. They have a big pushrod pinch though, so flow can be limited on higher HP builds.
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The magnum heads respond real well to porting. I have a 5.2 with ported magnums with the 1.97 in valve and they flowed 241 cfm at .500 lift. My little 5.2 with a ported m1 efi intake, hooker headers, 210/220 @ .050 cam and 8.86 to 1 comp ratio put down 290 rwhp. It ran a 13.69 @ 101.xx with a 2.94 gear. I figure about 340 at the flywheel with 15% loss. I wouldn't underestimate the power they can support.
 
X2 on ported Magnums.Would kill for a set of the MP Porting templates.
 
cdavis said:
The magnum heads respond real well to porting. I have a 5.2 with ported magnums with the 1.97 in valve and they flowed 241 cfm at .500 lift. My little 5.2 with a ported m1 efi intake, hooker headers, 210/220 @ .050 cam and 8.86 to 1 comp ratio put down 290 rwhp. It ran a 13.69 @ 101.xx with a 2.94 gear. I figure about 340 at the flywheel with 15% loss. I wouldn't underestimate the power they can support.
Click to expand...

I was speaking of in as is condition. Pushrod pinch or no, I think they are better than most J type heads un-ported. I don't have a flow bench for a comparison so I could be wrong...but just from what I have read and heard. Maybe Justin will chime in and let us know. I would certainly take his word for it.
 
Flow numbers,from Ryan @ Shady Dell :peak intake /215 cfm@ .500@ 28".They are in archives,I bookmarked.Moparts originally had the listing.
 
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