I have a 4 door Jimmy that I am replacing the fuel tank on. Everything is ready to reinstall, but I'm not able to lift tank with the straps in place. Unfortunately, I only have access to one jack and it'* currently in use on the frame rail.

Any suggestions on how to install the straps and still have enough room to connect the fuel pump lines etc?

you should not be working under a vehicle that is supported by the jack. there is no excuse, jackstands are cheap

Jack stands aren't an option right now as I'm broke spending all my $ on the gas tank, fuel pump, etc. With this being my only vehicle, any suggestions on getting it in place?

i have never tried doing it without a jack. unless you have a bunch of boards. i put a transmission in that way once, i could only lift one side at a time so i lifted up the front put a board in, lift the back etc so it went up even. takes a long time but it got done.

Got any 1" ratchet straps?

Being flat broke isn't an excuse for not having some sort of safety precaution for saving your *** when that jack fails. If need be place your spare tire under the back tire to lift it high enough to use your jack for the fuel tank. Sorry for the rant, hate see to see one injured or dead for something that could of been prevented.

The safety is everything.

For the tank replacement on the Jimmy, have the tank empty, that will allow you many options to lift and support the tank (like a milk crate). You can use a box, etc. The key is to have no weight in the tank, and that means no fuel in it.

You may need new gas tank holding straps, and may want to have them on standby and return them if not needed.