Rebuilt inline 250 on craigslist, Should I??

[Scottcoda]

Wow!! All fantastic responses!!! Thanks all for all the input.. I thought I would add a little more info to the conversation.. The owner does have receipts of the rebuild from a machine shop that is still in business, The motor was machined and is pretty much a brand new motor from 1972 (other than sitting for 9 years) I also know that the motor has been craigslist for sometime and feel pretty strongly I can pick it up between $500-600
I have been able to hunt Amazon and ebay to find some decent buys for my current 6 banger so I already have a Clifford intake, Holley 390, Headers, pertronix conversion, installed on my current plant.
I think I might pull the trigger, I really do love the the six bangers, Still apprehensive about the time it has been sitting but I guess sometimes things in life are a gamble..
I wonder since the motor was rebuilt if my performance upgrades would cost less money at the machine shop, I was thinking about doing a Performance valve job (194/1.6) replacing the pistons with 307 flat tops +.30 and having the lump ports installed, would having a clean head be cheaper to work on then one that has been running in a truck for 20 years??