I have an 86 s10 4x4 blazer. How do I know if I have the 20 gallon or 13 gallon fuel tank? I need to buy a new sending unit/fuel pump and not sure which one I need. I think I have the 20 gallon but how do I know for sure?

 

did you ever run it to almost empty? if you had to put more than 13-14 gallons in it you probably have the 20

 

Should show up in the RPO codes.

 

I cant remember (I have huffed too many resin fumes in my day to remember anything lol). RPO codes? Is that part of the vin?

 

RPO = regular production options
The label should be inside your glove box and lists all of the options installed on your truck. You can put those codes into any one of the available RPO decoders. Just run a search for "RPO+decoder" and you should turn up some working results.

 

NK2 - FUEL TANK 46L, 12 GAL, METAL


This is the RPO code I pulled from the glove box. It is neither 13 gal or 20 gal?!?!?! WTF?