Mopar P4532900 head info needed

-
pittsburghracer

pittsburghracer

Legandary Member
Legendary Member
Joined
Apr 20, 2016
Messages
17,732
Reaction score
41,130
Location
Freeport, PA.
Another head I’ve never had in my hands and a friend bought a set. He is bringing them over tonight to have me look at them. My first thought is the flow numbers look pathetic. He wasn’t sure on valve size but my thoughts are why tube a head and not run at least a 2.02 valve. Have any of you guys ran these heads and what did you think of them.

42EEDACE-84A3-4EB6-9E70-70DDAC7BA33A.jpeg


04477DA2-BB68-46B2-A0C8-5E95A72B27A7.jpeg


F6681D29-9038-4502-89CA-33C96E850B90.jpeg


6F6BCCFA-8B41-4D5D-8085-340A38D9C449.jpeg
 
Now see, if you switch over to slant sixes, you won't have to worry about all this "set" ****. All you need is ONE. LMAO
 
I’m not familiar enough with the various MP SB heads to know what that head is.
But as is the case with their other heads and intake manifolds, the number cast into the head is not the “part number”(the number in the catalog) for the head.

I assume you’re going to reflow it on your bench.

Edit- looking in my old MP catalog, based on appearance I’d say it’s the “aluminum magnum” head.
If it has 5/16” valve stems and 1.92/1.62 valves, and magnum intake mounting........it’s probably a P4876624.
 
Last edited:
PRH said:
I’m not familiar enough with the various MP SB heads to know what that head is.
But as is the case with their other heads and intake manifolds, the number cast into the head is not the “part number”(the number in the catalog) for the head.

I assume you’re going to reflow it on your bench.

Edit- looking in my old MP catalog, based on appearance I’d say it’s the “aluminum magnum” head.
If it has 5/16” valve stems and 1.92/1.62 valves, and magnum intake mounting........it’s probably a P4876624.
Click to expand...


I told him I can’t get into flowing them right now but for whatever good it would do I could look it over. After hearing what he paid for them I sure wish he would have called me first. It is for a magnum combo with I guess a hydraulic roller cam setup. He supposedly bought them from someone that bought them from Hughes.
 
That’s the MP aluminum Magnum “Commando” head right?
I don’t have a catalog handy at the moment.
That “Tubed” area looks closer to a Dam. Perhaps time for some seriously off set rockers and re-doing that pushrod tube.

These were not known to flow very well from jump street IIRC from back in the day. Just simply labeled as an upgraded head in aluminum at what ever percentage rate MP said they were over a stock head. 20% comes to mind but that could be horribly wrong.
 
rumblefish360 said:
That’s the MP aluminum Magnum “Commando” head right?
I don’t have a catalog handy at the moment.
That “Tubed” area looks closer to a Dam. Perhaps time for some seriously off set rockers and re-doing that pushrod tube.

These were not known to flow very well from jump street IIRC from back in the day. Just simply labeled as an upgraded head in aluminum at what ever percentage rate MP said they were over a stock head. 20% comes to mind but that could be horribly wrong.
Click to expand...


He’s no longer a racer but wanted a small upgrade. I won’t post what he paid but I’m sure he won’t be putting any extra money into them. I’m not sure what anyone things they gain from tubbing a head and porting it that way. Kinda beyond silly leaning towards stupid if you know what I mean. I’ve seen guys do that to the head bolt holes too.
 
My 2001 catalog shows the “aluminum commando” head as being used on LA motors.
3/8” valve stems and 2.02/1.60 valves, shaft rockers, LA intake mounting.

Same runner(177)/chamber(53) volume as the aluminum magnum head.
 
I haven't seen the "commando" la heads in person, but I was told they didn't flow well, no idea how bad they are, just what I've been told through the years. I'm sure you can make a significant improvement, but he "probably" shouldn't have bought those
 
I just noticed the flow numbers. Holy crap! "abysmal" would be my assesment. How much is he gonna pay you to fix them?
 
About four years ago, I had a chance to but a pair of the aluminum LA Commando heads. One was a finished head with the flow chart, the other was as cast. They were both the same part number and were close in appearance, except for the machine work. I called an old racing buddy and he said, in order to make the heads match would probably take a lot of money. The seller said he would take $200.00 for the pair. My friend said that once I had them matched up and purchased the valve train gear that I would have close to $2500.00 or more in them. Needless to say, I passed on them and bought some highly worked Edelbrock aluminum heads for less money. I haven't had the Edelbocks flow tested yet but the seller told me if I wasn't satisfied that he would refund my money. (Yes, I got that in writing.)
 
Hopefully, this weekend, if all things line up, I’ll have flow numbers from a stock OEM Magnum head. It would be on a local bench. So numbers between the reports are to be taken with a grain of salt.
 
replicaracer43 said:
I just noticed the flow numbers. Holy crap! "abysmal" would be my assesment. How much is he gonna pay you to fix them?
Click to expand...

Like I said no planned work on these. I could have done more on a single phone call before his purchase. Looking at those numbers those heads I’m assuming would need new bigger valves and 800.00 worth of work. But like I said he’s not a racer so I think it’s gonna be what it was. When I saw those flow numbers I thought I was reading the sheet wrong. But I wasn’t good old 25 inches of depression flowbench.
 
rumblefish360 said:
Hopefully, this weekend, if all things line up, I’ll have flow numbers from a stock OEM Magnum head. It would be on a local bench. So numbers between the reports are to be taken with a grain of salt.
Click to expand...
I think there are published numbers on the magnum R/T head somewhere too. I have a set of these on my crate 402 435hp motor. Apparently they benefit substantially from a mild port
 
Last edited:
I’d like to see a dyno run curve on that engine.
 
Is that the head with the exhaust ports that don’t match anyone’s previous header flange? Or extremely close to not matching up?
 
He had some stuff come up so we are going to try for Thursday. That will give me some time to study up some. Thanks guys.
 
rumblefish360 said:
I’d like to see a dyno run curve on that engine.
Click to expand...
I would too. I’ve seen 435 Hp at 5100 475 torque at 4400 and it makes over 400ft. Lbs From 2500 -5700. These are quoted from the ‘how to build big-inch mopar small blocks‘ book by Jim Szilagyi. He worked for mopar for many years in many performance capacities so it’s probably accurate.
 
You must log in or register to reply here.
-

Back
Top