Punishable by Death?

It's your call really, if the 289 can't be just honed and needs to be bored you'd have to step up to .060" which is farther than I would go and I have read of overheating issues going that far. Finding out if it'll take just a hone will be your deciding moment. These engines have lasted >40yrs. with 100's of thousands of miles, they wear out eventually or some PO overboars them or overheats them.

If it can't be saved I have seen other 289's for sale if you want to stay stock CID block or you can swith to a hyd. roller 302 which are bountiful and look the same cosmetically, many also decide to go with a later model roller 302 which are also plentiful. The roller parts are more expensive if you need to replace them (cam, lifters, etc. are ~3X what hyd. are but you don't have to break them in or worry about ZDDP additives).

If you check corral.net classifieds there are always people selling newly rebuilt motors to step up to the next biggest CID for more power so there are some good deals if you trust the seller or hear it run before buying. You might also want to price some crate motor short blocks and long blocks. Often the cost of a crate motor with warranty is the same as a rebuild.
Lots of options.
Jon

sparx said:

Problem is I want to get the HP up to around 300 and with the stock heads, intake, exhaust manifolds and the 2 barrel carb that is not likely.

sparx

Click to expand...

This is a very true statement. That would be demanding more than 1HP per cubic inch. An expectation of half that would be more realistic.

I have one of those 302s that a PO bored .060 over. Yeah, it doesn't do well idling in traffic in the summer. I have an original copper three core that I had rebuilt, but the volume of water the car can hold is low. Also, the '70 302 that I have required the lower pipe to be relocated to the driver's side. I consequently have very little room between the fan blades (factory V8 mustang original) and the rad pipes thereby eliminating the possibilty of a fan shroud. It should be noted that when this car was designed 50 years ago, it was with the view of open road freedom - not sitting in gridlock, as it didn't exist as it does today.

So, although an engine swap can be quite easy, there are the peripherals that can cause a few problems (or opportunities). A larger aftermarket aluminum rad complete with electric fans can be had for what seems like alot of money, but performance-wise may be well worth it depending on the value you place on the idiosyncracies of an old car in today's world versus the dependabilty we often demand and rely on.

But now I am rambling on...