The first thing you'll want to do is remove the engine from your car if you cannot get the oil pan off with the engine still in the vehicle. Before you're done it is always a good idea to cross check the new oil pump and oil pump pickup with the old one to make sure everything looks like it's assembled properly. If you are looking for the oil pump pickup it is pressed into the oil pump in many cases the whole assembly can be removed by removing one or two bolts near the bottom of your oil pump. At this time make sure that the rod fits into the base of the oil distributor properly if the rod does not fit properly into the distributor you will want to pull the oil High Efficiency Air Cooler
pump down and rotate the oil pump rod just enough and tried again. Do not force the oil pump pickup into the oil pump you don't want push it hard or give any sort of extra force. If you change the oil on your Chevy 350 crate engine regularly there should be little if any reason to change the oil pump at any regular intervals, typically oil pumps last for many miles before needing to be replaced. Pour STP into the oil pump and rotate the pump enough to make sure that it gets properly lubricated. Next remove the oil pump pickup in the oil pump itself. Now using a small hammer gently tap on the oil pump pickup housing making sure it is a match to your old oil pump pickup housing. If you need to replace the oil pump on a Chevy 350 engine this is a fairly big job and in many cases requires removal of the engine from the vehicle. Keep trying to fit in till the top of the rod fits perfectly into the distributor. If for some reason you've done your best and the oil pickup is not exactly in the same position it may hit the bottom of the oil pan or it may be too high to actually pick up the proper amount of oil..
If your vehicle is having problems with the oil pressure being low you'll want to make sure you check to see if one of the pickups is clogged or if you have clogged oil runners or bad bearings. You'll know you have achieved the right placement when you're able to bolt the oil pump to the block easily.
Once the oil pump and oil pump pickup is improper position you will want to prime the oil pump. When you are removing all the fluids from your engine be sure to use a different catch pan for the antifreeze as this cannot be mixed with the oil. Now both the oil pump to the block and replace your engine and all fluids in reverse order from when you originally removed them. This type of job typically requires that you have two people and it is recommended that at least one of you be a very seasoned and experienced auto mechanic. You want to make sure to dispose of all of the fluids properly and then place the engine on a proper engine stand for temporary storage. Simply place the oil pump pickup into the oil pump so it stays but it is loose.
Now you'll want to insert your new oil pump assembly into your engine block.
Once the engine is secured outside of the vehicle you want to remove the oil pan.
Now that you've purchased your new oil pump you want to take the new oil pump pickup and install it into your new oil pump. If you discover that the problem is centered around the bearings or if for some other reason you need to remove your vehicle's engine at this point you should replace the oil pump whether it is bad or not because you already have the engine out of the vehicle