I know this has probably been asked a million times but if i wanted to make my 289 into a 302 do i have to get the block bored out or do i just use different rods, pistons, etc.

thanks

 

302 is a stroked 289 basically. Different crank I suppose. Using the 289 rods will give a smaller piston to deck clearance if desired.
So the 2 differences are stroke and connecting rod length.
While your at it, find some early 351w heads for more flow. They can be adapted easily.
Low dollar power options...

 

They are the same motor. The stoke is just a bit longer on a 302. If you want to make a 302, just bore it. I got my 289 bored .30 over.

 

So how many cubes is a 289 bored .030" over? Not 0.30", no such thing!
How much overbore is required to take a 289 to a 302?
Now is the time to stop the BS

 

A 289 bored .030 is a 293. You can't get 302 cubes out of a 289 by just boring it out.
Even with a max. of a .060 overbore you only get a 297

If you want a 302, then just go find a 302....they are a dime a dozen.

 

Thanks Slayer, for helping to end the BS.

 

Some people need to be nicer. If you bore a 289 you still have one of the best motors ford made! You don't have to bore it. The 289 is great for the mustang! The is no BS about that.

 

The 289 and 302 both share the same 4.00" bore. The 302 has a slightly longer stroke. You can convert your 289 into a 302 by using a 302 rotating assembly in your 289 block. IIRC, some lower cylinder wall work is required to accomodate the longer stroke. As has been mentioned, you're probably better off just getting a 302 to start with.

 

Not trying to not be nice...just want the facts out there, not guesses or biased opinions, otherwise know as BS. I guess we can all be guilty of that at some time or another...