should I use any sealant? i don't have the luxury to pull the block, or rather i have the convenience of leaving it in haha

 

I'd use permatex and maybe upgrade to brass plugs. They conform easier than steel, and no rust. Be sure to wire brush or sand the opening smooth.

 

I used the adjustable ones from O'Reilys 2"-2.125" the directions said no sealant. Old ones rusted out at 250,000 miles now I have 270,400 miles and no leaks.

 

If you need to replace any freeze plugs, while you have them out get a coat hanger & feel around inside the water jacket.

If you can pull out any rusty metal shavings, then try to get out as much as you can. Sometimes the machining chips are left inside there, & cause the freeze plugs to rust through. those chips can also cause the engine to run much hotter, since they block the flow of coolant.