I have a 65 coupe with a 289 2 barrel. It is time to start working on getting the old stock motor up to 300 hp.  I already have new hooker full length headers and a dual exhaust with flowmasters.  I would like some advice on a good set of heads to buy without breaking the bank.  Also, I have a stock 4 barrel intake from a 66 mustang but no carb yet which I plan on either a 500 cfm or 600 cfm later.  I am putting off the cam selection until later also since there are so many size options to use.  I am running a 4 speed top loader and stock 3.00-1 gears right now.  

Probably the best heads for that application would be the AFR 165 street heads.  But they will run you around $1400 complete.  There is also the Edelbrock 2091 package that will get you there but it'll want more gear than what you have now.  Dart Iron Eagles have a 58cc chamber and run about $530 each at Summit Racing.  World Products has a decent street head with a 58 cc chamber, they run about $410 at Summit.  With 9:0~9.5:1 compression and around a 220 intake duration cam (roller better but not required) you should get your 300 HP.  I would not recommend using the stock intake, use at least an Edelbrock Air Gap and use intake gaskets that block the exhaust crossover.  If you insist on the stock intake, block the crossover and run a heat shield+non metallic spacer under the carb.  It get's really hot.  Either a 500 or 600 carb will do, you won't know the difference unless you're racing it on the weekends.  If it's a street car, get the 500 Edelbrock and put an electric choke kit on it.  If anybody gives you a hassle about a small carb, remind 'em there's a billion small block circle track motors making 400~500HP and limited to running Holley 500CFM two barrels.  

All good advice there for you Kane...

I will add that my '66, when the 289 was rebuilt, we wanted to give it a very stock/stealthy look. It is using the stock iron 4V intake, but we had it Extrude Honed. With CNC ported iron heads (again to keep it stock looking, but aluminum or aftermarket iron heads will be better), Extrude Honed Hi-Po manifolds, and a Comp roller cam, we made 281hp on the engine dyno. I was basically looking for Hi-Po numbers without the solid cam, and we got it. This was also with a very mildly tweaked Autolite 4100 (best stock carb ever made). With better exhaust (like you are planning), a more performane oriented intake, and some careful machining/building you'll easily hit 300. Most 289s I've seen with aluminum heads, air-gap style intake, and a Holley or Edelbrock carb are running in the 320 range...

HTH...
Mark  

I'll throw in the build we ran in the Mustang - it's a 302, but same applies.  Flat top short block, zero deck, GT-40 iron heads (351W Lightning heads) cut to 60 cc chambers for 9.5:1, mild intake runner pocket porting, good exhaust porting (not big flow, like 190 intake, 145 exhaust @ .500), stock 351W valve size, 216/228 Crane hydro flat tappet cam (H272-2 if I remember right), Performer Air Gap intake, Holley 600 DP carb.  This engine made about 270 HP, more or less.  Pulled a 3350 lb 1970 Mustang to 13.03 @ 103MPH in the 1/4.  

another option is to go with the paxton supercharger.   you will still need to build the engine for reliability, but you can also build it for economy.  With a real mild build, mild cam extrude honed heads and an aluminum intake or even better aluminum heads for more weight reduction, you can build an engine that has all the horsepower you want with decent fuel economy when you aren't hot rodding.  obviously not the most economical way to build horsepower but I just happen to love the look and feel of the paxton so I think everyone should have one.  

Thanks for all the input.  I looked up the edelbrock 2091 kit and like the specs it had.  The HP figures they had were for a 302 but should be close enough for a 289.  It seems like the best bang-for-the-buck way to go. Unless I run accross someone selling a 302 from an 87-93 mustang pretty cheap!