Question for a P-pump pro
 

I just found a cheap 98 stick donor vehicle for my chevy swap. The down side is the guy already stole the pump to swap onto his 95 but will give me his old one instead. Is there actually a difference in pump design or were the later pumps just tuned differently from the factory. Therefore can the 95 pump be tuned to the 98 level or will it always fall short?

both being p-pumps ??? VE & VP pumps suck !

Yes, both P-pumps.

I AM BY NO MEANS AN EXPERT, more like a curiosity question, isn't a 98 electronic p-pump as where the 95 would be fully mechanical pump?

98 was a split year. Model year 98 had the mechanical P-7100 pump as well as the electronically controlled VP-44.

That being said, to tell you the stock power ratings I would need to know the what transmission each truck had. The p-pumps on standard trucks are rated higher and there are only minor differences between the years. Rest assured, a 95 pump can put out just as much hp as a 98 provided it has the correct mods and tuning.

i am no expert, but i swapped my 97 manuel p-pump or a 96 automatic p-pump. the ratings were different as the 97 being a standard was rating for more hp. you couldn't tell the difference tho since i wasn't racing the truck i was just driving normally. pulled just as hard and ran just as good. hope that helps

something to think about, if the 98 works on the 95, why wouldn't the 95 work on the 98. question is why would you swap the pumps unless something is wrong with it?

:humm:i jsut thought of that same thing.

Quick answer; very different. Different cams, plungers, delivery valves, and governor assemblies. The pump from the '95 either an 838 or 841 will make quite a bit of power, the only downside is the cam design, but it won't come into play unless you wish to exceed 4000RPM.

^^ Theres your expert opinion ^^


You can still make a lot of power with a 95 pump.

No sir, there's no such thing as an electronic p pump. As someone else mentioned, the 24 valve engine with the electronic vp44 pump replaced the 12 valve engine with the p pump in 1998, but only the vp44 pump has any electronics. Maybe that's what you were thinking of?

The seller swaped out his 95 for the 98 because of the higher factory set power output.

Grinding your fuel plate to a different profile, installing an aftermarket fuel plate or removing the plate altogether will far exceed the "factory set" HP rating. Of course, its not quite that simple - you need to do some supporting mods and some tuning may be involved, but you get the general idea.

i changed my pump myself and that was a total PITA! i don't see why anyone would go through that (unless building a racing truck) for the extra hp? i'd have to agree with evil when i could throw a plate in and tune the afc much easier get noticeable differences. just trying to make sure your not getting shafted by the seller trying to pawn off a busted pump on ya. i'd hate to see anyone buy a not running truck and the parts that were given to them to make it a running truck be in none working condition, cause these pumps aren't cheap....

Yes there is.

Just curious to what they were put on. :c:

i too am curious as to what an electronic p pump was put on and weither or not it be put on the 2gen cummins. wondering what kind of percs there would be to it???

im not a complete expert on them. but im pretty sure they came on bigger trucks. they basically made it able to have more fuel and timing but yet it can retard it for easy starting. but correct me if im wrong. bc i have a few junkyards for big trucks around me that have them pumps on them. i forget the name but i wana say its a PE7100?? not sure. also if you need a pump why dont u go to the truck boneyard a get a 14mm pump off a dump truck or rig with a 5.9?

I never heard of those. Learn something new every day. I guess I should redo my statement then: P7100's, as installed on dodge trucks, were never electronic.