Closed Deck Blocks

Ok thinking of doing a engine biuld for my blob eye, picking up bits as and when i can afford them, can u use an old block to start with or do they get weaker with age and miles ?

depends on what youre wanting to build up mate. what crank etc. early blocks like the cdb used a centre thrust crank not rear thrust like the later blocks meaning you cant put in a later sooper dooper STI nitrided crank into one without having it machined lol. if youre picking up bits as you can afford them then you'll be replacing the bearings i'd hope and using forged pistons which have new rings so its not exactly gonna be weaker. will be like a new engine