I rebuilt a 72 short block 350 to put in a 87 tbi Chevy with an RV cam where does the timing need to be set at?

Answer 1

If you're still using the TBI and a stock distributor with no advance weights or springs and no vacuum advance you'll probably end up with the timing pretty close to the stock factory specs -- there's no way to re-curve the ignition timing curve other than to put an aftermarket prom chip in the ECM (i.e. superchip etc.).

You're kinda limited with today's pump gas anyway and can't get real carried away with the timing. Advancing it a few degree's beyond the stock specs might be OK, just watch out for pre-ignition -- if you put a load on the engine and start hearing spark knock or pinging you have to back it off or you'll damage your new engine. If it runs good with the timing set to stock specs then there's no reason to change it, if it feels a little sluggish and you advance it a few degrees and it runs better and doesn't ping/rattle under a load then you're good to go. Just don't get too carried away, an RV cam is usually a good stock replacement cam and doesn't require you to make radical tuning changes.

All of this assumes you were asking about ignition timing and not camshaft timing as the cam timing specs should have come with the cam and you would have checked and adjusted that when you assembled the engine.