Magnum replacement heads

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replicaracer43

Grumpy Old Man
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So it seems the EQ replacement casting are being discontinued, but I see that JEGs are selling a "made in USA" replacement casting, that are definitely NOT EQs... Has anyone had any experience with them yet?
 
I just noticed that too. Hughes Engines also just posted a note the other day saying EQ castings have changed, and they are not to be considered as viable performance parts.
Did EQ discontinue both Magnum castings for sure, or did they change the 318A and discontinue the 318B?
At least we still have the Edelbrock Magnum heads. They are a good piece.
 
I willing to bet the jegs heads are cast iron speedmaster heads....just look identical to them..
 
A Speedmaster head that’s made in the USA???

Hhhmmmmm
Yeah, that doesn't sound right. It does say "made in USA" and I noticed Hughes engines made a technical note on there website that "EQ" replacements heads (these??) were not recommended for any performance work. They do have a abysmal looking seat area, and the short turn isnt as gradual and rounded as even a stock magnum head.
 
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Did you buy the new Jeg's heads? Is that what the chamber pictures are showing?
If they are yours, please post a few more pictures, from different angles.
 
Did you buy the new Jeg's heads? Is that what the chamber pictures are showing?
If they are yours, please post a few more pictures, from different angles.
They are for a customer, trying to determine if they are even feasible for a mild performance build
 
The seat work sure looks very similar to:

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Unless it’s a very stock type build, I’d suggest a little clean up in the bowls.

It’s hard to imagine they’d be any worse for a “mild performance” build than stock magnum heads.
So, if you think stock heads(or tweaked stock heads) would get you were you wanna be.......I would imagine those will as well.

Unless you can get one flowed, and have some numbers from a stock head from the same bench....... it’s all speculation as to how good or bad those are.

The EQ’s were a noticeable improvement over an OE magnum head.
 
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The seat work sure looks very similar to:

View attachment 1715507088

View attachment 1715507089

Unless it’s a very stock type build, I’d suggest a little clean up in the bowls.

It’s hard to imagine they’d be any worse for a “mild performance” build than stock magnum heads.
So, if you think stock heads(or tweaked stock heads) would get you were you wanna be.......I would imagine those will as well.

Unless you can get one flowed, and have some numbers from a stock head from the same bench....... it’s all speculation as to how good or bad those are.

The EQ’s were a noticeable improvement over an OE magnum head.
Thanks, I appreciate the input! I am not sure why there is a big step above the valve seat, almost like its counter bored down to far. It shrouds the valve pretty bad. Guides are pretty loose too, looks like .316, and the stem is .312 on the dot. I can fix the issues with guide liners and some seat work, but still concerned about the short turn
 
I got a set of these on a core motor, look a lot like a factory heads but they have inserts in the intake and exhaust seats, I believe they would probably be good for stockish builds but the ports arnrt near as pretty as eq,s. Not a single number cast or stamped on them that I can remember.
 
Took some pictures today ....Speedmaster cast iron....EQ magnum head....Indy LA-X head.,,,plus a TA Head...

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Speedmaster head has freeze plug at end....EQ and Indy LA-X do not....look at the end of the head for the alternator,,,,

the EQ head and Indy La-x head were machine and assembled by Imm in Indio ca,

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It’s a pic off the net, so it means next to nothing, but the one on the Jegs site has the freeze plug.

Tony, any chance of getting a close up pic of the valve seats on that SM head?

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I’d be pretty(very?) surprised if the Jegs head and the SM head aren’t the same heads....... where ever they come from.
 
Thanks, I appreciate the input! I am not sure why there is a big step above the valve seat, almost like its counter bored down to far. It shrouds the valve pretty bad. Guides are pretty loose too, looks like .316, and the stem is .312 on the dot. I can fix the issues with guide liners and some seat work, but still concerned about the short turn

That’s why they make grinders....... so you can fix that stuff :usflag:
 
Yes...i will take some tomorrow....Valve Seats>?

The speedmaster casting is dark compared to the EQ or Indy also
 
The local machine shop got some EQ heads about a month ago in Canada... maybe there are some in warehouses up here... might be worth it with the exchange rate
 
Yes...i will take some tomorrow....Valve Seats>?

The speedmaster casting is dark compared to the EQ or Indy also
I noticed these castings are very dark also, and the smell something awful, strange really
 
The real question is can a hack like myself, make something decent out of them. That's why I do appreciate any input or advice on them. I do have the ability to machine them, just not 100% sure what all needs done. Guide size seems to be 8mm on these, and his old magnum OEM castings have .312 stems in guides that are just about .314. I thought all magnums were 8mm?
 
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