Couple of questions about changing fuel tank

[jawjadawg]

I have an 85 GMC Jimmy Sierra Classic 6.2L diesel 4wd. My tank appears to be leaking, and the fuel gauge doesn't work properly. I THINK the tank is 25 gallons. I've never put anywhere near 31 gallons in when fueling up. Questions are:

1) Will a 31 gallon tank fit, or does the tank size need to remain the same? Summit seems to carry 31 and 40 gal tanks. I assume if I would need new straps for a larger tank, but not sure the larger tank will fit.
2) Is the fuel pump part of the sending unit? I have seen some units that include a pump, but not sure if they fit my vehicle (even though I have typed in the make/model/year).
3) What are the best sources and brands to buy? Summit has Dorman and Spectra. Is Summit high on their prices for this stuff?

Thanks so much, and appreciate any additional input or tips you guys might have to add.
Jawjadawg

 

[diesel4me]

I'm not sure,but most 6.2's that vintage had only the mechanical lift pump on the engine,none in the fuel tank .(my '85 Suburban with a 6.2 is set up that way,has a 40 gallon tank)...the newer body style '88 and up trucks also had an electric pump near the tank on the frame rail also in addition to the mechanical pump..

I don't know what the smallest diesel K5 tank capacity is,but if it is less than 31 gallons ,then the original straps would likely be too short and you'd have to buy the ones listed for the 31 gallon tank..I'm thinking only Suburbans had 31 or 40 gallon tanks optional ,not K5's,but again,I'm not sure what they came with standard equipment..

My friend installs a lot of Spectre tanks and has had very few problems with them..most say made in Canada on them..he gets a healthy discount from a local supplier and also uses a lot of their radiators..