If you've got ur timing cover off and the chain has a bit of slop then ya may as well change it. If ya can move the chain back and forth and it moves more then about 5mm or so I'd change it. Every Holden V8 I've pulled apart, stock and modded, have all had double row chains. I normally just replace them anyways. Rollmaster billet sets cost about $140 for 9kw version (9 keyways in the crank sprocket to adjust cam timing)...but there is a more basic version without the extra keyways which is probably a bit cheaper.
If it was mine tho I'd just rip the whole motor out and give it a birthday lol. I've got a good 253 which was rebuilt by Richards Motors bout 3-4 years ago...has only done maybe 2000km's since. I might sell that if ur keen? I'd prolly be after around $500 for the short motor. But really if u do start spending money on a 253....you'll regret it later and wish u just bought a 308 lol.
What r ur plans for the Kinga? Could buy a trimatic pattern 308 bottom end and chuck EFI on top of it. All bolt in, no rego hassles, more reliable and better on fuel, PLUS THE HEADS ARE MADE TO RUN ON ULP!!
