Speedmaster Head Bolts?

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Squishy

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I'm using Speedmaster aluminum heads on a 5.9 Magnum block and have not been able to scrounge up any information on which ARP head bolt set will work. I don't have a stock Magnum head to measure the depth of the bolt bosses so I can't compare from one head to the other. I would assume the aluminum head has a thicker bolt boss?
ARP basically makes two sets for the magnum , a stock replacement(144-3604), and the Edelbrock Magnum head (144-3605).

Has anyone had to figure this out, and what was your fix?
 
Just find two OE long bolts.

It’s not something trick.

If you look at the head you will see (looking at the drivers side) the bolt boss between 1 and 3 is taller than the bolt boss between 5 and 7 on a stock head.

Thats because Chrysler save a couple of ounces of iron per head by leaving the bolt boss that doesn’t have oil coming up through it shorter.

Back in the day the dumb asses at Chrysler did the same thing on the W2 castings.

And when you fully port a W2 head (or an iron passenger car head) you will break into that head bolt boss.

So Chrysler rather than sending out a tech bulletin and just telling guys how to fix it, they made up a little “kit” and sold it through Direct Connection.

All it was is a piece of round stock with a hole in it that you epoxy in place and then use the long bolt on it.

I forget what it retailed for but a first week machine shop student could make one out of a drop or some other scrap.

So it’s not new.
 
I'm using Speedmaster aluminum heads on a 5.9 Magnum block and have not been able to scrounge up any information on which ARP head bolt set will work. I don't have a stock Magnum head to measure the depth of the bolt bosses so I can't compare from one head to the other. I would assume the aluminum head has a thicker bolt boss?
ARP basically makes two sets for the magnum , a stock replacement(144-3604), and the Edelbrock Magnum head (144-3605).

Has anyone had to figure this out, and what was your fix?
If you have Speedmaster aluminum heads for small block Mopar, they are basically copies of LA style Edelbrock heads. They take the same bolt or stud kit that LA style Edelbrock heads take.

It does not matter that you have a magnum block. Other than making sure you figure out how you will oil the rocker arms.
 

If you have Speedmaster aluminum heads for small block Mopar, they are basically copies of LA style Edelbrock heads. They take the same bolt or stud kit that LA style Edelbrock heads take.

It does not matter that you have a magnum block. Other than making sure you figure out how you will oil the rocker arms.
After looking at my heads again, they will need the LA head bolts. I have the conversion rocker arms from Mancini to oil through the pushrods.
 
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