[Dangerous Doug]

289ERAKIT:
I've looked into this myself. Everything I found was that on a 289 0.040" over is the max if you are going to drive this in traffic and expect it to not overheat. If you' drag racing (short, hot runs then shutting down) then you could get away with 0.060" over, so I'm told.
I was going the rebuild direction recently with a 289 that I have. The machine shop I went to wanted to go 0.060" over. This indicated to me that he was more of a Chevy specialist than a Ford (he should know to take it to 0.040" max if he's read anything about SBF's). My machine shop wanted to charge me $7600 for a long block assembly rebuild* (Dart heads, comp cams, built with "interesting" HP, but nothing spectacular). I found essentially the same engine options (with a warranty!) from T&L Engines for $4000. You can also get a respectable long block assembly from Ford Racing for about $3500 (see Summit Racing catalog). So, if you're trying to save some money by rebuilding you will probably spend the same amount in machine work and shop time as you would on a long block from T&L or from Ford Racing. Incidentally, if you really just want an engine for your ride, I saw "basic" long block assembly's in Mustangs Unlimited for $1800 (stock engine---and that included a $300 core charge). Don't stop looking there. Check Coast High Performance, Keith Craft, et cetera.

So, unless you're wanting to build an out and out mind blowing 289 (and in that event, you should be talking to Gessford, or the likes, NOT your local machine shop) you can get a better deal for the cash you're going to shell out by buying a long block from a reputable source that's churning them out of a factory.

DD

* Note: I was originally quoted $7600 for my 289 rebuild. This sounded high to me, and it didn't include the options I wanted, so I opted out of this deal. I later found out that the Speed shop in question "has difficulty finishing projects" and that other customers have run into "severe cost overruns". One project at this shop has been going on for over a year and is over $100k in cost overruns (custom, chopped Suburban, I am told). I am SO glad i didn't go with this local shop.