supose I want to replace my camshaft with a larger camshaft. what all do i need to replace that would i have to change the rockers, rod, lifters (I kno I have to if i change the type "hydrolic, flat tappet, Roller") what all doI need to do? Also what kind of cam does a 1967 289 have?

 

I'll give you the best advice I can on this one after a lot of motors over the years.
Call your preferred Cam manufacture. Comp cams are mine. I told them what I was building ,where I wanted it be power wise and then the questions from their end came.
Things I didnt think of what size wheels and tires what gears auto or stick? What do you want to do with the car? Drag, road race, autocross or cruiser.
Between CompCams, AFR and MSD tech they helped me put together a beast.
The surprise was each company referred me to the other. AFR told me call COMP and so on.

However I found Holly and Paxton to pretty much suck with that no help what so ever.
Comp Cams gave me more info on my s/c than Paxton did Same with AFR and Compcams helped me pick the right carb They told me the exact same unit based off the info I gave them. Holly just tried to refer me to a High$$$$ tuner they are in with.

These guys spend major Bucks on R&D so they know about these things.
I didnt use to be this way years back other than a good parts guy @ the Downey or Napa you were on your own.

Sorry about the rants.LOL
In short all the info you need is on the tech lines. They know more than anyone else about what works with what.

 

well I am in high school i dont want a drag car but i want a beast but then again what teenage guy with a 67 mustang doesnt. i want that hard idol looping sound but i want it reliable and decent gas i want good low and midrange horsepower and same in torque but do i have to replace anything other then the cam and lifters if i install a larger duration cam?

 

what your looking for is a hyd. flat tappet cam and lifter set, a double roller timing chain, and a cam swap gasket set. hardened pushrods are a good upgrade while your at it.

NOW, the above will work with cams under .475 lift (but even that is pushing it, .450 is probably a safer number - of course thats too damn small to be any fun)........ so, spend the money on new stiffer valvesprings / retainers / keepers to match your cam and while the springs are off you can throw new valve seals on there (umbrella are very very cheap from any machine shop, probably like 5.00 for the set).

lastly, once you start bringing the spring pressure and the cam lift up, you need to look at your pressed in rocker arm studs..... getting them pulled and tapped for screw in studs is a job for a machine shop, which means the heads are coming off the motor. this also means you should be upgrading to some roller rockers.

how much money did you want to spend again?

cliff notes: do it right, spend lots of money OR save a buck and use a moderate sized cam and replace very little

 

Also, you're not gonna have a beast with justa cam. And the hard lope at idle comes from a cam that generally doesn't make good low end torque and mileage either. If you want a good cam then definately get springs/retainers etc, and upgrade to screw in studs and roller rockers. But a good cam won't work to it's potential unless you have good heads, good compression, good intake, good exhaust and good ignition. Engines are a package deal, you change one thing you basically change it all, unless you make a change that's close to stock, in which case there's not much point in spending the time or the money, just save up till you can make bigger and better changes, such as heads etc.