I want to replace my instrument cluster with one that has all four gauges, right now I have two (Fuel and Temp) and I want the one with all four (Fuel, Temp, Oil and Battery)

I have a 79 F100 with the straight six.

What models will work with the speedo cable and electrical connector?

And, do I need to change the sending units for the oil and battery or anything else?

 

I think you need a 76 or newer cluster, I have a 76 and older one for sale BTW you can also look for them in E class van's up to mid 80's ?

 

Unfortunately switching to gauges from idiot lights is not an easy thing to do. The fuel and temp aren't a problem. For the oil pressure you need to change the sending unit and the wiring itself is different. The ammeter is the big problem. To use the factory ammeter you will need to change the alternator wiring harness and the main (dash) wiring harness. This is a bit of work and in the end the factory ammeter probably isn't going to work! Even when the trucks were new the ammeters were notorious for not working.
IMO you're better off installing a set of QUALITY aftermarket gauges. The info will be more accurate and the installation a lot easier.

 

Thanks for the information, looks like after market gauges are the way to go.