I have been trying to drive my old '77 280z as much as possible, my problem is when you step on the gas a little to hard it acts like the clutch is slipping. my thoughts were that my dad did not replace it and the car now has 418,177 miles. going thru some of his old repair records, back in 3/17/04 he had the clutch, master cylinder, release arm and pivot ball replaced with 400,000 miles on the odometer. clutch slave cylinder was replaced on 2/16/04. I have not had much time to check things out, just wanted some advice as to what should i look at.

Might just need an adjustment. 18000 isn't a lot of miles on the clutch, depending of course on the way it was driven.

My dad was in his 70's and did not drive this car very hard, is there any threads on how to adjust the clutch ?

I'm with Bart on this. Can you smell clutch (smells like brakes) when it slips? If it is a simple adjustment, do it now before it becomes a clutch/pressure plate problem. The FSM is your friend on this one.

No i can't smell anything, didn't think about that. The clutch went out on my '95 eclipse GS-T, i drive this car like i stole it, and it would smell for a while after you park it .

If it is like the 240Z on the slave cylinder rod you can adjust the nut to adjust the clutch. If you get under their, provided the same setup, you will see it is pretty easy to do.