school me on a 5.9 magnum motor.

[340sFastback]

that would be nice.. wonder what their turn around time is.. shipping may be expensive too..

Shipping a fortune. Hughes sells new Magnum heads prob sufficient cast iron around ports for 340 manifolds. So you can spend your way out of head aches buy new Magnum heads LA intake bolt pattern likely 340 exhaust bolts on no adapters improved castings that don't crack quench chambers erc etc etc etc....

 

[DionR]

Shipping a fortune. Hughes sells new Magnum heads prob sufficient cast iron around ports for 340 manifolds. So you can spend your way out of head aches buy new Magnum heads LA intake bolt pattern likely 340 exhaust bolts on no adapters improved castings that don't crack quench chambers erc etc etc etc....

Based on the pictures on the website, the only iron Magnum head Hughes lists doesn’t appear to have the needed material to seal 340 manifolds. Plus they have the Magnum intake bolt pattern and would require the extra cost of redrilling them if you wanted to run an LA intake.

The aluminum heads offered look to maybe have enough meat around the port, but it’s just a guess as I am only looking at pictures on the web.

 

[HankRearden]

Here is a picture of a magnum head and la manifold out of my scrap pile.
You can see the mismatch that would cause an exhaust leak.

If I were going to put thos together I would weld up the opening in the manifold kind of squaring it off to match the head.

 

[sireland67]

I built a 5.9 with Edelbrock heads, and a 340 with X heads about the same time.
I broke both of them in on my engine start stand, using the same headers (generic steering thru the headers car style).
Using the same name brand header gaskets, with no leaks.

I then had a change of plans and put the mag in my 78 W150, and bought the standard truck style headers (Headman). Never did have gasket issue.

My guess is the exhaust ports are the same, but again, not 100% sure the Edelbrock used a factory magnum port.