LA Parts in Magnum Block?

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js1023

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Hello all

Ok, So I been saving up for some years now to build a Dodge 360 LA series. Well I bought a motor off a buddy, and bout 1500$ worth of bearings and comp cam kit. So I took block and heads to the machine shop. Machine shop told me to many cracks in the in the heasd, and block was salvageable but needed to be bored out.

I am looking for the cheapest way to fix up a decent motor. Can I get a magnum block and heads from the running durango, ram, jeep Cherokee etc. and use the XE268H Comp cam? and bearings?

This is major parts that I have.
Bearing Set
4 inch pistons
20-223-3 XE268H Cam Kit with chain
professional prodecut air gap intake
650 Cfm carb double pumper.

Can I use the LA block with mag heads? with a carb?

Any input or suggestions would be great!
 
yes,,,,you can magnum heads on a LA block...

besides the heads and rocker arms...you will need lifters that oil thru the pushrods...check to see if there is a hole in the top of your lifters ...

also you will need pushrods that allow oiling thru pushrods...

LA heads oil thru block to shafts in heads to rockers...magnum oil thru lifter to pushrod to rocker
 
Welcome. This is a pretty common issue....cracks in the valve seats of your heads. The block needs to be bored? Were you just anticipating a Hone and Re-Ring?

I know how machine shops are.....At first they always say "oh yeah...we'll vat that block and get it all cleaned up" THEN they start claiming the cylinders are Pine Barrell Shaped, and needing all kinds of, Align boring, sonic testing, magnafluxing, ect....to rack up the $$$$.

If you cannot physically feel a ridge at the top of the cylinder with your fingernail, and no scratch in the bore will catch a fingernail, tell them to install new cam bearings, hone the cylinders and give it back to you before they end up in your sock, instead of your pocket.

I have a set of workable cylinder heads....your choice 587 castings or 308's.
Hit me up via PM.

Good Luck.
 
Machine shop told me to many cracks in the in the heasd, and block was salvageable but needed to be bored out. Machine shop told me to many cracks in the in the heasd, and block was salvageable but needed to be bored out.

I am looking for the cheapest way to fix up a decent motor.
Click to expand...

This is normaly the case. Bore the block out with a hone plate to the smallest possible oversize.

Return your pistons for the size needed for the blocks overbore. If the pisons are fordged, the machinest will need the pistons before overboreing the block for proper fitment of each piston. This is how it's done with fordged pistons. Hyper-U / cast slugs do not need this step.

New heads can be obtained easy. Best step up is probably Edelbrock or Indy X heads in the "LA" configuration.

Can I get a magnum block and heads from the running durango, ram, jeep Cherokee etc. and use the XE268H Comp cam? and bearings?
Click to expand...

Yes you could, but it isn't all that simple. If you get a Magnum block & heads, (Which would be a waste of money at this point since your current block is ready to be machined) you would need AMC lifters (More money) and hollow pushrods to feed the Magnum valve train oil. (More money) The Pro-Products intake has dual intake bolt patterns, so your good there.

The bearings are only good for the crank journal size, so if your current crank is cut down , the bearings are sized to that crank and not a standard crank, which may or may not need cutting.

P.S. Your undercarbed.
 
OH, there could be a piston issue with the Magnum heads, what pistons do you have?
 
Prine said:
Welcome. This is a pretty common issue....cracks in the valve seats of your heads. The block needs to be bored? Were you just anticipating a Hone and Re-Ring?
.
Click to expand...

Yea...block needs to be bored, yes thats all I was anticipating to have done.

PM will be sent
 
Those are good slugs. They come in the MoPar short blocks and create engines. I just took apart a create shortblcok myself.

With the Magnum heads, you'll have to figure the new ratio with the reduced head chamber size. There ,015 shorter than the KB-107's, which come in at 9.8-1 with a 72cc head chamber and .039 head gasket. There probably 9.5-1 with the same head.
Excellent pump gas street strip ratio.
 
So what I am getting from a lot of replies and advice here, I can defentily use the magnum heads. Build the block as if I was going to bolt on the LA heads. If I am unable to find a decent set of LA heads and I got the Junk yard or something and pick up some Magnum heads I need to check my lifers are get push rods that have the oil holes on them Right?

Now is there only certain years of the Magnum series I can use? What about the head gasket...Can I use the one that came in the LA series rebuild kit, and same with the in the intake Gasket?
 
Thanks everybody for the Input and advice this is something that caught by surprise....But the is the fun of building a motor
 
With the Magnum heads recuced chamber, you'll go from 9.8-1 to 10.2-1 - 10.6 -1, gasket dimentions can effect the actual ratio and where the piston ends up sitting. Thus the spread in ratio above. You can use the LA gasket on a Magnum engine. The bolt holes on the Magnum heads may not be a perfect line up with the LA head gaskets. You'll need to ethier modify the LA head gasket, - AKA cut holes or get Magnum head gaskets.

I'd just use LA heads. You can use any Magnum head. You'll need to get hollow pushrods and know if the lifters you have are OK to use for this. Often, AMC lifters are surplied in the MoPar kits.

You will also have to recalculate the lift. Magnum heads have a 1.6 rocker, where the LA heads have a 1.5 rocker. This is easy to figure out. Just take the lift of the cam, say, .480, divide by 1.5 and the multiply by 1.6 for the new lift. The math looks like this.

.480 / 1.5 = .32
.32 X's 1.6 = .512

New valve springs must be sought to handle the new lift.
 
Prine said:
Welcome. This is a pretty common issue....cracks in the valve seats of your heads. The block needs to be bored? Were you just anticipating a Hone and Re-Ring?

I know how machine shops are.....At first they always say "oh yeah...we'll vat that block and get it all cleaned up" THEN they start claiming the cylinders are Pine Barrell Shaped, and needing all kinds of, Align boring, sonic testing, magnafluxing, ect....to rack up the $$$$.

If you cannot physically feel a ridge at the top of the cylinder with your fingernail, and no scratch in the bore will catch a fingernail, tell them to install new cam bearings, hone the cylinders and give it back to you before they end up in your sock, instead of your pocket.

I have a set of workable cylinder heads....your choice 587 castings or 308's.
Hit me up via PM.

Good Luck.
Click to expand...

haha! good call!
I have recently been through this and you don't want to know who with.
freaking crooks. Overpriced to begin with and then crooks on top of it. I must not look like someone who measures all my own stuff.

Maybe next time I'll show up with filthy sweatpants and a black tshirt with a hole in the armpit like everyone else.:angry7:
 
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