What cam specs are in it now?
(can't go bigger until we know where ya are now!!!)

Besides cam swap a bump in CR boost seat-of-the-pants....
Headers/free flow exhaust(2" tubing) will help...
PLEASE .......tell me you have maximized your timing curve !! (36* total advance all in by 1800 or so RPM)
6sally6

yes if you better have a good gear to match that cam.
 

3.0 gear will not work with much of a cam.   There are “RV” grinds that are smooth and will work.  Sounds like you already have one?

Drives good.
Idles well.
22 mpg.

You sound just like me.  “This is working very well.  Let me see how bad I can screw it up.”

The BEST thing to do is pull the heads and have them shaved(check with the machinist how much) ....
...3 angle valve job
...grind out "the hump" in the exhaust ports
...gasket match the ports (slightly open and smooth the EXHAUST ports)
This alone will give a nice 'boost' in your 289 engine.

Cam change will require spring changes....screw-in studs(at least have them pinned)
I will always have a camshaft custom ground before I pay 'the-same-price for an off-the-shelf ground camshaft'.
Delta Cams ground mine and I can't say enough nice things about them. They (Ken) had lotsa good advice about what to
do for your goals for the engine.
Intake duration.....204*
exhaust................214*
Lift.....................  .460
LSA..................... 112*       (110* for a little snotty-er idle......108* for the 6sally6 seal of approval !! )

I bet.....they recommend something along those lines.
250-260+ HP should be the end result.....
Be sure and check-your-wallet before starting and remember 'MS motto'.
6sally6

BobE wrote:

Toploader - I agree with MS, sounds you've got a nice ride now, if you're not ready to do other upgrades, just be careful, things can go south real fast.
You haven't mentioned the carburetor brand and size that your currently using, and the intake manifold. 

You guys are probably right and I don't want to upset the apple cart here.
For what it's worth, the carburettor is the Autolite 4100. Great carb by the way!

Making more power with a NA engine is a complicated question to which a lot of people seek an easy answer.  Many of us can tell stories about how we ruined a perfectly good combination in the quest for a little more.

The big issue you have is that the stockish 289 cams in the hydraulic cam engines are designed to be done by about 5,000 RPM.  They did this to give the engine some low end grunt, because the engine is small and doesn't make a ton of torque.  When you start increasing the cam specs its going to shift the power upwards in the RPM range, but you are going to me moving peak torque, which is going to cost you that low end grunt. 

There are ways to change the setup to get the low end back, or make its loss unnoticeable, but they also come with consequences.  One of the simplest is do what Ford did with the HiPo cars, more gear.  Swap to a 4xx gearset and it'll be very peppy out of the hole, even with a big cam.  Of course, 22MPG is going to go bye, bye and your RPM on the highway is going to increase substantially.

The other option is build a bigger engine.  More cubes means more torque, so even though the torque peak may move up there's probably still as much torque in the lower RPM range as the smaller engine had, maybe even more.  The biggest consequence here is the dent its going to put in your wallet.  Most of the stuff I've read will tell you the older 289 is not an ideal candidate for a stroker, plus the benefit of going to a 5.0 block and having the ability to run a cheap roller cam is hard to pass up, so likely you are looking at an engine swap vs. a rebuild of the current engine.  Saddling a stroker with stock heads doesn't make much sense either, and on, and on cost wise.

Now, you can target a mild upgrade and modify the heads, though at the cost of all that work you are probably getting close to entry level aluminum heads like Edelbrock.  Increasing the CR will make it snappier, but you're going to need to run premium fuel.  Then you can swap the cam, and all this nets you maybe 20HP.  The problem is that its the same cost as adding 100HP.

My thoughts are think this over long and hard.  I don't think its worth spending $1,500 to get 20HP, or get more HP at a higher RPM and ruin so much of what makes the car fun to drive.  I'd rather bank that money and build a better engine that will make 100HP more and not make so many compromises.

The only other option, and I'll just throw this out there as it can give you 20-100HP pretty easy, is nitrous.  Power is there when you want it, not when you don't.  It doesn't change the current combination at all.  The only issue is having to get that bottle refilled, and that it can be habit forming.