Finally!

my dream has come true. haha
im gettin a beautiful 240!
its an 89 with only 97,000 miles. sadly there is a good amount of rust on the frame behind the tires but thats ok

i do have a question, is it safe to cut out the rusted parts on the frame and weld in some plates? or would this destroy the frames rigidity?

depends on what part is rusted. if i understand correctly its behind the tires, in other words behind the suspension mounting points, therefore not the frame as you say and not structural. oh wait did you mean behind the front or rear tires? if its behind the front tires then its kind of iffy. the 240sx doesnt have a frame, per se, and pinch weld/underbody rust is often a sign of the beginning of the end. you can weld in new metal but the amount of time, thought, and skill put into this task will determine how much the structure will be affected. either way, without some significant bracing and repair i wouldnt try and race or drift it. of course this depends on the extent of the rust.

behind the front tires, as in under the firewall. when i can ill take pictures of the damage. it seems prety bad yet fixable, a few inches long but i was searching on other forums and people say you can go to the nissan dealer and get the frame rails that are rusted and have them wleded on. being that its a unibody how will this work? are there any other alternatives to fixing this or would it have to be all cut out and replaced with new metal?

the body of the car provides all the structural integrity in a unibody, so new metal must be used. how effective the repairs are is determined by how much work you put in finding good enough metal(i.e. dont use a big hunk of whatevers lying in your garage), and the quality of welding.

ya i get it. and when i fix it i plan on gettin quality metal and my cousin is going to do the welding because....well i dont know how to. and i trust his skills. he built his own frame for his 32 ford in his garage. so if theres a way to fix it im doing it.

i have pics of how bad it is ill post em as soon as i get them on the computer

thanks