well i am back in the saddle again....just picked up my new ride and looking for some input. bought a 98 2500 that started out life as a v-10 auto and was transformed to 12v cummins with nv4500. truck is 4x4 extended cab with 4 doors, clean as a whistle and runs great. owner said that the v-10 croaked and he had a guy that specializes in this do the swap. motor was taken from a 93 that was totaled with 200k miles on it. he took everything from donor and then went to dealer for pedal assy and other things to make change clean. noticed today though that when i filled up the tank, gauge went all the way to empty.......took 22 gallons to fill and gauge was on almost full when i filled it. thought i better fill it to check mileage and was surprised to see gauge do this. if that is the only hiccup....i will live with that. all other gauges appear to work properly, temp seems a little low but i will check that one on next road trip. what kind of mileage can i expect and any mods or preventative maintenance i should do. my previous trucks were 24 v and long ago had a 91 2500 12v getrag 5spd. any input would be appreciated.

 

You should see mileage comparable with your old 91, the VE pumped trucks always seemed to do better.

 

thanks for the input, i have however forgotten what i would get in my old 12v.......oldzheimers kickin in i think. i am trying to fiqure out what size tires to go with on it. it is a 12v with nv4500 trans and 3.55 gears. i will be driving to work and light towing with it. nothing real heavy like huge trailers or anything, mostly pontoon boat to lake and such. when i am on the highway doing 60, tach is showing 1900 to 2000 rpm. i want to be able to do 70-75 on hwy and not crater the motor. truck currently has 235/85r16 tires on it and they look stuuuupid. i have ordered a leveling kit for it and want to go up in tire size, was looking into 285's or 315's. what do you think would be a good size for it and allow me to keep up with traffic on the highway. truck has a ton of low end grunt, but it feels like rpm's are getting too high at 60 mph. what kind of "tweeks" can you put on this setup to improve mileage and power if needed? thanks again for the advise.

 

ok basics here. so do the kdp. ill tell u what i did to my gig and what it roughly cost (canadian dollars) depending on how much u wanna 'tweak' it id get gauges. not necesarry for some ppl but if ur like me and most others a little basic 'tweaking' will turn u into a diesel power freak i got a autometer setup around 270. then i pulled the fuel plate. u may wanna go a little less agressive perhaps and still run a plate of ur choice though. valve springs and gsk. get the 4kgsk right away just trust me thatll make it fun as soon as u get a clutch thatll hold the power. then tune! it took me a looong time to do it but now i wish i did it right away. tune the afc, do the free mods. spend the couple hours it takes and u will have a truck thats amazingly streetable (smokeless) and have seamless endless power. thatll all i have for power-waiting to do the timing next. now mileage. when i first got it it had 265s and was bone stock. i got 21.4 mpg (always hand calc'd). then i put on 315x12.5x16 on a still stock truck and got 23.5 mpg.i ended up puting in a leveling kit to end the rubbing issue and am happy with the 35s now. havent had it on a long road trip since all the power mods were added but i cant wait cause i expect it to b just as good or better. especially with that timing bump. long story short, mpgs are directly related to how u drive. i got 19 mpg town driving. ya. on 35s. lots of help on here if u use google and the search button. most ppl would tell u to just search but i know what its like being new and not even knowing what to search for so there, i helped u out. enjoy

 

DC, Don't forget, he has a conversion with a VE pump, not a P7100.

Bill, think you had better check the gear sets, 235-85-16 is what I run up here for snow, they can't be beat. Probably does look like the kid next door with skinny legs down there though. I run about 1750 or so in 5th at 60 with known 3.55's, so something isn't right there.

Since you have a VE pump you need to slide over on the first gen side and let those boys help you out. I know you will want a 3200 spring and a fuel pin, but past that can't help.

 

Sry, I absolutely missed that then then ignore most of what I said and ya fuel pin, 3200 springs and maybe turn the pump for some timing? my first gen knowledge just ended.....lol but with my 35s and 3.55s I turn a hair under 1600 @60 mph......