I'm new to this but I wanted to check with the experts out there. Is there much performance difference between a W31 (7040255) carb versus a W30 (7040258) carb? Also, I thought an original W31 is the rarest oldsmobile carburetor. Is this true? Last, my friend says that a W30 (7040258) carb is worth more money. What do you guys say?

 

The W31 carb use a smaller pri jet, # .057, and no pri rods. The 258 carb is a W30 auto, and it uses pri rods, so it has bigger jets .069. The W30 MT is like the W31 carb no pri rods. Both carbs are worth some money to the right person. The W30 MT carb #7040256, is probably the one worth the most money.

 

Thanks for the information! I know there are a lot of fake carbs out there. I pickup an original 255 carb years ago but it is incorrect for my W30. Just still haven't located a 258 carb yet. I found someone who wants to trade but says that the W30 carb is worth more; so he wants the carb + $. But I just don't know if the 258 carb is real. You wouldn't happen to know a way to tell if a 258 carb is real ???

 

I sold my original 7029255 carb last summer for $500. It was probably worth more. The buyer was VERY happy with the deal.

 

You can tell a lot of times if a carb has been restamped, unless it is a real good job. Also on the 255 carb, take it apart and see if it has pri mettering rods. Even if it was restamped, I would bet they did not change the inside, as most guys probably don't even know they are different inside.

 

do you want to sell that w31 qjet or what?

im still waiting.

 

The 7040255 is still available. I checked the stamping and it reads:

7040255 NA
0900

Let me know if you are interested because it is still for sale.

 

you did real good.

i was offerred a 9255 a couple months ago for $250.

it was on ebay.

 

Not sure if you can make a comparison between the 7049255 carb in 1969 to the 7040255 carb in 1970. Pricing is on different spectrums. I have one person who is willing to trade a spare 1970 ram air hood for the 7040255 carb. That is about a $2000 value. Personally, I don't think the carb (or a 7040258) is worth that much. I have one other person willing to swap my 0255 carb with an 0258 carb which is what I need.

 

you put this carb up for sale on this board.

i pmed you for the price of the carb,and that i wanted it.

no reply on my pm,and i see this in the topic.

do you really have this carb?

 

 

You DO realize this thread is from 2009, right?