I need info for porting the exhaust port on this head on the short side (how deep?)also, since bottom end is stock what is an accurate Compression Ratio for these 53mL chambered heads?
(Application is 5.9l SB stock bottom end)

Here is a close up of the port(s).

Wierd, looks like some funky upside down A.M.C. port.Considering it will go on a stock bottom end,I would thin the extra width around the guide,and polish the rest. The short side looks to have a pretty large/tall radius already.Should flow good enough for a stock lower end.

I think how much porting you want to do will depend on what cam you are going too run, is it just the stock cam? If it is just a stock cam then grinding much out won't do any good, just smooth out the rough areas around machining transitions and if you have the rough cast heads there is a lot of rough stuff in there to clean out. Any more than that and it will not do any good. The pushrod pinch in the intake port is pretty bad so might want to open that up a little, I don't think that would hurt on a stock motor, also the bump in the intake roof from the rocker boss can be removed but you have to run a thread sealler on the studs or bolts or oil can be sucked through around the threads.

I have set like that I was going to use but may end up selling them to pay for the rest of my motor and I will just run ported stock heads and hope they don't crack too bad.

Good points, the cam is 0.506 lift @ 227/234. So do not elongate the vertical access on the exhaust to match the gasket?

Okay fellas, I have been lightly porting around the valve stems and cleaning up the exhaust. I still need some info on these heads. I assume that not many people are running them since they have such a small combustion chamber, but surely someone has used them or know someone that is.

Remove that knob. Open the ex to about 1/16 smaller than the gasket all the way around. The PR pinch is really small so open it up as much as you can with out makeing holes into other parts of the head. With your cam exotic max porting is not nessacary.

Not many people are useing thease heads because they were so over priced when new it was incredibly rediculous. You could buy complete eddys with springs valves retainers... for less than thease cost new and the eddys flow more OOTB.

Do you have any more specific questions you need help with?

I don't know about that. I don't think "removing" that knob would be a good idea. That's the boss for the pedestal rocker. At least if your going all out. I could see, at least if going to studs, that being a weak point created. Actually I'd be more apt to expoxy the whole side of the port after the pinch and shape it like the cast iron heads.

my memory is fuzzy
... but I think that Larry Shepard wrote an article about those MP Magnum Aluminum cylinder heads in Mopar Performance News magazine many years ago and it would be worth tracking that down.

I believe that Shepard wrote the AL Magnum heads were worth 20 hp, just bolted on, because memory tells me I pulled out the calculator and made an estimate of what the greater compression ratio alone would be expected to make in increased hp

Perhaps someone here on Moparts has the article and could scan it in

I am even fuzzier on whether official MP porting templates were offered in the catalog that year for Aluminum Magnum heads,
but something tells me they were

One thing is certain
.... MP offered CNC ported Iron Magnum Cylinder heads in the catalog, (Magnum RT CNC ported too) so somewhere there is a machining program set up

Since you have a new set of Aluminum Magnum cylinder heads
why not go down to a local Hobby Shop and buy some of that plastic molding compound
and make at least one mold each
of the left and right handed ports?

Post deleted by siggie30

And the exhaust???

I would raise the exhaust opening but not lower it.

Don't cut the exhaust floor like that; just square up the port and blend the SS. You are going to need to get the chamber machined on those heads or they will flow less than the worst 318 smog head for better than 2/3 of the lift curve. I'd hack that whole stud boss out of the intake port. It looks like you have that intake gasket hanging too low judging from the bolt holes. Best way to eyeball it is mock it up with the intake manifold on the engine and take a look at what you got. PR pinch will need to be opened too. You can get a Helgesen E-tool to measure the pinch from Dr-J's Performance, google them for their website. Port it where it counts; with those heads you can't be dusting the china cupboard and ignore the stampeeding elephant in the room.
-dulcich

The previous picture with the note "alignment tab". It seems that if this tab were not there that the gasket and the intake openings would better be aligned. Is there a reference to aligning the intake to the head intake port that I do not already see. Since I haven't really started on the intake side (at the entrance) I would just like to do this once (or rather 8 times) and be allright. Would it be simpler to mark the heads and intake together and move the gasket to match them up (taking into account the shimmed difference of course)?
EDIT: Okay so after the "mock up" it is apparent where everything goes. I am concerned about removing the rocker bolt casting as these are aluminum heads and the amount of material that would be left for the bolt concerns me for longevity and strength (100 shot N2O will be used).

How much extra strain you figure the 100 shot puts on the rocker studs? What size are the studs anyway? if they are small like 5/16 oem drill and tap for 7/16 chevy studs. You don't need that big boss, almost all aftermarket heads just run the studs throught the port roof. A little teflon sealant and you are good. How much thickess is left if you knock the whole boss out?
-dulcich

If I grind out the hump- it leaves just a hair over 5/8" thickness. The studs are 3/8".

I agree. I think you are right. I should of not posted it that way, but hey- first time builder. I found out after putting the stuff on the block how the gaskets really should be oriented . Thanks for not flaming btw.

Here are a few shots of the rough port work. I really just need someone to say "hey, your messing that up" or "finish polishing what you have there". the line toward the valve is the referenced area in the next post.