ok thanks what about the sending unit in the tank should i able to hear it??? i did the mod to the lp so when i trun the key it runs

No there is no pump in the tank.

Not a great idea to do the LP mod that way,should you get in an accident and get knocked out-fuel will keep pumping and BBQ you and anyone else around.

The OPS is used for that safety function-when the engine quits so does the LP.

ok so ur telling me that the sending unit dose not do noting but just set there

The sending unit is just 2 tubes and the fuel gauge.
1 tube to pull fuel out and 1 to return it to the tank.

The vent for the filler neck is also incorporated.

EG:
http://www.ebay.com/itm/2000-Chevy-3500-6-5-diesel-fuel-sending-unit-/280899981380?pt=Motors_Car_Truck_Parts_Accessories&hash=item4166f19044&vxp=mtr

thank you what part store do you recommed to get the sending unit from where i live we have napa advanced auto and auto zone

Doesn't really matter what store you go to it will likely be a dorman or a spectra.

Just don't use the included pick up sock-take it off and add an outside screen or re use the original GM one with the trap door in it.

If you have dual tanks be sure to let them know,the frt tank takes a different sending unit than the single or rear tank.

This explains one of my headaches. My tank has too much suction. every time I take the gas cap off I can hear the tank expanding back to its original size. I replaced the gas cap hoping that would take care of the issue but no luck. It must be the sending unit vent.

The sending unit vent only hooks to the 5/8" hose on the filler neck-the filler cap still has to vent the whole thing so you must have gotten the wrong filler cap or a bad 1.

It should be green or have a large D on it or both-parts guys think they know best and often give out gasser caps when only a diesel cap will work.

thanks again

got it fixed it was the sending unit thanks alot