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Need help - replacing heads on a 426 Wedge block but....

akintosyali

New member
I pulled the head of the port engine as it lost compression, took it to the machine shop (very reputable, they know their stuff) and they called saying my heads have multiple hairline cracks and they are beyond repair.

Here is the issue:
the casting on the block is :2406730: So this confirms I have a 1963-65 426 RB Bigblock wedge/Maxwedge block (based on this link: https://www.enginelabs.com/engine-tech/a-guide-to-mopar-v8-cylinder-head-and-block-casting-numbers/)

The casting on the headers are 2406516. this is for a
1964-1967, 361/383 B/RB-series big-block, 2.08/1.60 valves, 73.5cc (not a wedge!)

Instead, it should have been:
2406518 – 1964, 426 B/RB-series big-block, 2.08/1.88 valves, Max Wedge, 86cc

There are NO cast iron replacement heads. The only thing I can find is replacement aluminum heads.

Replacement options for a 1965 wedge engines are:
Edelbrock E-Street Cylinder Heads for Big Block Chrysler Part Number: 350-5090
Port Volume: 210cc/70cc, 75cc Combustion Chambers, Valve Size: 2.14"/1.81" OR

Edelbrock E-Street Cylinder Heads for Big Block Chrysler Part Number: 350-5093
Port Volume: 210cc/70cc, 84cc Combustion Chambers, Valve Size: 2.14"/1.81"

The first head is closer to the current heads for cc volume. The second one is close to the cc of a wedge, but neither replacement head has the same valve sizes.

I am stumped! Any advice would be highly appreciated.
 
I would say you will be very lucky to find a pair of '518 heads that are in very good shape.

If your shop 'knows their stuff', I'd be inclined to go with their suggestion provided they know what 'marine engine' means. If you have a closed cooling system, aluminum heads shouldn't be any concern...If you have a raw water system, the aluminum heads will have a finite service life if you have any significant mineral content in your home body of water.
 
FWIW, All those "b" blocks and "rb" block Chryslers are "wedge" engines due to the head combustion port shape unless it's the "rb" 426 Hemi. A couple differences between wedge heads is valve size and closed or open chamber ports.
"Here is the issue:
the casting on the block is :2406730: So this confirms I have a 1963-65 426 RB Bigblock wedge/Maxwedge block (based on this link: https://www.enginelabs.com/engine-tech/a-guide-to-mopar-v8-cylinder-head-and-block-casting-numbers/)
"

"Max Wedge" is an HP engine package for a 413 or 426 wedge engine. Max Wedge heads have larger exhaust valves and ports with manifolds to match.
A 413 or 426 "wedge" can and have used standard production heads with hydraulic valve gear. The 413 may need notches for larger exhaust valve clearance.

Mopar B/RB - Heads | www.darkside.ca

As you can see in 300hb's link there are no heat cross over ports.

FWIW, The Edelbrock "available" dates have been getting pushed out later and later no matter what Mopar big block head you're looking for.
BTW, Here's their MW head.....
Edelbrock 77949: Victor Max Wedge Cylinder Head for Big Block Chrysler - JEGS High Performance
There are 440 Source heads available now.
Not seeing TrickFlow available yet.
 
I think your heads stamped "2406516" are original. I have the same heads on my dual quad carb 426 Marine engine from 1964 (called "Golden Lion 325" as a marine engine). The "2406518" dont not have heat passes on the heads. I have pulled out this engine due to a cracked block and replaced with a 440.
 
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