Dodge LA to magnum heads

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Brodrdude

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My stock la heads are cracked to the point of no return. I have fresh stock magnum heads. I seen it have to get the amc lifters and hollow push rods.
Can I use the the stock shaft/rockers from the LA.
Use the stock push rod length at 7.5inches?
 
Since Magnum heads don't use shaft mount rockers, no. You'll need to measure for correct pushrod length.
 
RustyRatRod said:
I thought I was clear. Magnum heads don't use rocker shafts.
Click to expand...

This Style of rockers where on the head before hand
Would this work?
Screenshot_20210811-142747.png
 
Brodrdude said:
Please bare with me, imma scrub in learning
So I have this style late 80s model la head. Do it have to do anything special to make it work? Or just plug and play

View attachment 1715779733
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The LA head like pictured uses shaft mount rockers. The Magnum heads like you talked about changing to do not.
 
What RustyRatRod is trying to tell you is magnum heads have pedestal mounted rockers. La's have shaft mounted rockers. So no shaft style will work with magnum heads
 
dartfreak75 said:
Those are not magnum heads.
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Indeed they arent magnum heads, I shouldve litting more investigating they just looked alot different then my other la heads but this late 80s model wont make a difference compared to the stocks from the 70s?
 
Maybe there’s a confusion between LA roller block and magnum?
 
Brodrdude said:
My stock la heads are cracked to the point of no return. I have fresh stock magnum heads. I seen it have to get the amc lifters and hollow push rods.
Can I use the the stock shaft/rockers from the LA.
Use the stock push rod length at 7.5inches?
Click to expand...
No.

Magnum push rods are 6.95 long, valves are stock sbc length, 8mm stem.
Rockers are pedestal bolt mounted but can be switched to stud mount and guide plate. Std LA Shafts will not bolt on. There are or were some shaft mount rocker setups for these .

Oil through pushrods are what you need to keep the top end slick. You dont want to assume on the length. Hey it together and measure for proper length 'figuring in the preload of course '
 
And possibly lifters depending on which ones your 318 has. AMC lifters are the correct diameter and pump oil through the hollow Magnum pushrods to lube the rockers and cool the valve springs. Yes, oil does cool the valve springs. Magnum heads also take a different intake manifold. The bolt holes are vertical compared to the angled ones on the LA heads.
 
Brodrdude said:
Indeed they arent magnum heads, I shouldve litting more investigating they just looked alot different then my other la heads but this late 80s model wont make a difference compared to the stocks from the 70s?
Click to expand...
The LA head in that picture is a late 70s looking casting.
It has air injection. Early 70's pre mid 1974 did not... though the spread out center exhaust ports lend to a 308 casting from the late 80's into '1990/91, then the magnum was introduced
 
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toolmanmike said:
Probably a rebuilt 302 head.
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I edited my previous post when I pondered why you thought 302 when I noticed the exhuast port size.
My bad, it's a 308 head.
Or that other part number for the 308.
I bet you were looking at those exhaust ports being spaced out huh? But the 302 should have its casting on the top as well as 714 ..while the 308 sometimes is not or mostly is not actually and is on the bottom and you'll see that 25 cast in and usually a half moon type design or something like that
 
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What casting head are you replacing? There are compression ratio difference based on the combustion chamber size. Also, if your old heads are early ones, along with your exhaust manifolds, you'll need to plug the air pump holes below the exhaust ports, or, you will leak exhaust. If you're working on a '64-6, you'll also need to grind some clearance on the driver side rear exhaust port for the factory manifold to bolt down.
 
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F yeah, 7 posts to tell the guy Magnum heads have pedestal mounted rockers! Cut the newb some slack. We were all there once.
 
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