I recently bought a fully built (used) 200 block bottom end with a view to fit it to my 2wd head to go in my 3dr.

It arrived last week and i've noticed that all the pistons have impact marks on them where obiously previosly valves have hit them (i'm suspecting the car it came out of had a timing issue/cam belt failure etc)

this means that all the pistons have 2 little "cuts" in their top face that havent been machined there. My question is can i still use them (if i take the rough edge off the impact mark) or will they need replacing? Appart from these little marks (about 3-4mm long and 1mm deep) the pistons look in good condition.

Thanks!

 

yeh taht will be alright

wouldnt worry

 

Mine have got them in - could have been a number of things that have caused it, when timed it up wrong or when i drove it on the red line either way it still operated perfectly

 

These marks are VERY normal for the cossie, and don't normally cause any issue at all, the marks on mine were about 1/2" long, normally caused by tired valve springs not closing quick enough at very high revs, from your description it's perfectly safe to use.
tabetha