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I’ve searched and read a whole bunch of threads about swapping an HO(028) pump in place of an SO(027) pump the mixed answeres really leave a guy confused. 

 

So so I don’t care about high horsepower capabilities or anything like that I’m just interested in daily drivability with at most a small tune and some 50-75hp injectors but currently bone stock. 

 

My SO pump is dead, I have a known working HO pump. What can I expect by swapping the HO in place of the SO pump. Many say it works just fine and many others say it can not be done..

Edited by skyhigh4by

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  • It will work fine, many have done it.  If it is cheap / free do it.  Otherwise just replace the so with a so.    

  • You are hearing the timing and pressure differences between the pumps.

  • Literally 100% depends on how far you want to push it. Both have made over 800hp to the wheels.

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It will work fine, many have done it.  If it is cheap / free do it.  Otherwise just replace the so with a so.

 

 

Why would you you trade out a truck with a H.O. pump for a S.O.? I know h.o. has higher pressure and s.o. has a bigger internal piston size( or more area I guess) but what makes one better than the other? I also know you can make more power with a s.o., but is it just better built all the way around?

 

12 hours ago, Alexio Auditore said:

Why would you you trade out a truck with a H.O. pump for a S.O.? I know h.o. has higher pressure and s.o. has a bigger internal piston size( or more area I guess) but what makes one better than the other? I also know you can make more power with a s.o., but is it just better built all the way around?

 

 

This. Most times that’s all people seem to care about.

Op doesn't care he just wants his truck running again.

Edited by Me78569

And he has a pump he does not have to buy.

Edited by dripley

Oh... I wasn’t implying that was the OP’s point of view. Just saying in general most people choose the SO pump given then choice because of the hp gainzzz

  • Owner
On 2/11/2018 at 7:52 AM, notlimah said:

I also know you can make more power with a s.o.,

 

Even the Hotrod VP44 is only 21 HP over a stock SO pump. The only thing that makes a Hotrod pump what it is... When they are built they use a mixture of both HO and SO pumps. Gives it a slightly more advanced timing and more volume of fuel. Gain between HO and SO in stock form is only 10 HP. Not like we are talking about a whole bunch... :wink:

My dad has a 99 with the s.o. pump, his truck is bone stock. Compared to mine, which is the 2001 with the h.o. pump, his seems much quieter and smoother sounding too, but maybe it's just coincidence. That's why I was curious if one pump is built better than the other besides higher hp gains. I know my pump is approaching the end of its days , so when it comes, I'm just wanting to make the better decision, if there is one ( not going with a hotrod)

You are hearing the timing and pressure differences between the pumps.

  • Owner
8 hours ago, Alexio Auditore said:

so when it comes, I'm just wanting to make the better decision, if there is one

 

I suggest you stay with the stock HO pump. 

1 hour ago, Mopar1973Man said:

 

I suggest you stay with the stock HO pump. 

Why ? isn't with quad v2 SO would be a better choice? Reason I'm asking is I'm not sure on health of my vp and from passed readings people say SO is the way to go unless you just doing rv275 then HO is better option because of slightly higher pressure for atomization. 

  • Owner

There is the rare time where the crossing of the HO / SO boundary didn't go so good. Then you have to watch who you buy from being if you swap pumps you lose your core money. If you buy a SO typically they want a SO core not a HO. So be aware of this. 

I have an HO motor and will stick with an HO pump since I would loose the core for not having the proper core. Just me though.

How much power is an HO pump capable of?

I imagine I'll never see 500 hp, so if its easily capable of that, then no point in going with SO

Literally 100% depends on how far you want to push it. Both have made over 800hp to the wheels.

I suppose with v2 tuning and right turbo/injectors combo it would be marginal. 

Even if Ho was 600hp max that is more than enough for a DD/tow truck. 

I'm probably going to get a used SO some day if I can find a good one that I can trust and see if there is any difference, but I doubt I'd notice it with my set up. 

My plan was never to get rid of my HO for a core to get SO most places will take HO for So but not the other way around, at least that was the case few years back when I was thinking about it. 

But if I can score a good used SO of someone I'd definitely keep HO for a spear on the shelf, or under the seat lol.