Hi Cleandan
I assume you have checked and are sure your 289 is a five bolt block. Most are six bolt. Here are my recommendations when going to a six bolt block.
Install a good 302. The Ford iron head crate engine is cheaper and better than a rebuild.
Newer, 302 engines, since 1968 I believe, require a flywheel and front damper for a 50 ounce out of balance so don’t use your 289 flywheel or front damper!
If the new engine has a serpentine accessory drive, you must swap the front cover, pulleys, generator or alternator. You can use the 289 water pump but Tthis is a good time to install a new one. The water pump pulley-mounting flange will have to be pressed back to align the belt. The original crankshaft pulley can be used if you machine the mounting face on most new dampers back to align the belt and drill the pulley for four holes instead of three. A new Ford crate engine front damper is hard to convert to a “V” belt pulley so you will need to replace it.
The 302 probably has four exhaust gas recirclation ports in the heads. They must be plugged. You can buy special Ford plugs.One of those ports on the right side head becomes the pivot bolt for the alternator/generator adjustment arm.
If you are using rocker covers from your 289 you my have an interference with the end rocker arms. You may be able to fix the problem by using two gaskets. Check this out before you install the engine. The later covers have more room.
Assuming you want to stick with the Ford four speed top loader, you will have replace the clutch housing with a six bolt housing and use the Mark II slave cylinder, unless you want to use a hydraulic throw out bearing. Replace the clutch, the throwout bearing, install a roller pilot bearing with the right diameter and a new pressure plate.
If you plan on using the same distributor you must replace the drive gear with the one recommended by Ford in their racing catalog or you will destroy the cam shaft. They are identified with an orange paint. One of them fits the shaft of the older distributor.
You may use the intake and carburetor of the 289 but you would save some weight with a good aluminum one. Don’t get one that is too high or you will have to cut a hole in the hood. The Edelbrock Performer 2121 works if you use a minimum of carburetor spacers. If you happen to use aluminum heads, lift the powertrain by the exhaust mounting surfaces, not the carburetor mounting surface. Your carburetor should be 600 cfm or less.
Use your 289 oil pan and oil pick-up tube to the oil pump. Put the dipstick in the 289 front cover and plug the dipstick hole in the side left side of the block. It’s best to tap the hole with a 1/8 inch pipe tap with the pan off so you can catch the iron chips.
You will have to re-plumb your heater, find a place for the stock temperature pick up, transfer the oil pressure pick up and other small things like that. Everything else, such as the engine mounts , exhaust manifolds etc. will bolt right on.