Ford Repair: 302 Stroker, aluminum heads, mercury montego

Question
I have a 302 block that I just removed all the internals from and am planning to build a stroker out it, assuming there is no block damage.  This block is from a late 60s, early 70s Mercury Montego and I was told it overheated.  When I drop this off at the machine shop, what should be my concerns, i.e. I don't want them doing work when the block is useless.

So assuming it is okay...I am torn between a 331 or a 347 stroker kit.  I have heard the engine life for the 347 is lower.  I am building this for a little street rod.  I just want something that really hauls.  What kind of power difference can I expect between the two?  And if it becomes a daily driver, are strokers going to last 100K miles?

And would a set of GT40 heads be a wise investment?

Answer
Jordan-

  When you drop the block off, have them magnaflux it to check for cracks and have them check how well the bores have kept their round as well as how straight the deck surface is.  Essentially just have them give it a good once over.  If everything checks out, I'd go with a 331 kit.  You will give up a little power versus the 347, but it will also last longer than a 347.  As long as you don't skimp on the kit I don't see any reason the engine couldn't live for 75K-100K miles before it needed a rebuild.  Just remember...you get what you pay for and cheap kits are cheap for a reason.  The kits that have impressed me the most are the ones from DSS Racing and Coast High Performance.  As for the heads...I wouldn't go with GT40s.  The aluminum heads are decent, but they suffer from technology lag on the order of 10 years or so.  There are so many other heads on the market right now that would easily overpower the GT40s.  For a 331 stroker something like AFR 185s or Canfields would work great and for not much more than a set of GT40s.  Hope this helps.

Steve