I have a 1990 Dodge D150 that was converted to a W150 before I got it. I just finished the 4 inch lift on the truck and it has small 31s with the 15 inch rims on it right now. I’m wanting to put the 34s on it with steel 17s. How bad will it be for the truck with 3.23 gearing. I don’t care about gas mileage or power I’ve modified the engine some to make about 300 horsepower so power isn’t my concern.

 

What trans is in it?

With the bigger tires, and LOW (numerically) gearing, it's gonna be a dog off the line.

 

are you sure it has 3.23 gears? 3.55 were starting to be common in 90 with overdrive. it will be slow. dodge would run 31's from the factory with 31's on the older 4x4. the transmission may not like it but it will turn them. my 89 had 33's on it when i first bought it. they looked good but pretty slow to get going.

 

it’s the 727 for the small blocks

 

I don’t think it had overdrive if so it’s out because it catches 3rd at about 55-60 mph then doesn’t go any faster then about 80 in 3rd

 

you may not have overdrive now but the truck may have come with it originally. is the speedo accurate? should be able to do more than 80mph even without over drive with 3.23 gears and 31. if the truck had 4.10 or 4.56 gears it might max out around 80mph

 

I live in Texas so mostly flat lands but high winds and on a bit windy day it tops out at 80 but with wind 70 at most. The rear differential tag says 3.2 on it but I could pull the cover and count the teeth to see if they ever had the gearing swapped. The previous owner used it as a 5th wheel farm truck it has a custom built 5th wheel ball welded to the frame.