I decided to break the parts by type (coolant, fuel injection, cylinder head, etc), but also by necessity. A "C" means the part is absolutely necesary for the conversion; an "M" means that the part is a maintenance item and should be replaced; an "O" means that the part could be replaced while you're down there, but is not necessary, and a "U" denotes a part that is an upgrade over stock. I've included the approximate prices for both new and used parts, but like old underwear, there are some things that you just don't want second hand, so I've placed an "NR" (as in Not Recommended) in the areas where I don't recommend buying used (1). Other than the custom pistons, I chose not to list aftermarket parts (cam, fuel pressure regulator, injectors, mass air sensor, etc) , so the following parts are all factory issue. However, some factory upgrades are listed.

If you add all the figures up from the "new" column, the total comes out to something like $9411.50. Now, before you soil yourself, remember that this figure is for ALL brand new parts, many of which you probably don't need and many of which you can get on eBay for cheap (who pays $1700 for a differential anyway?). The prices are for a reference only and shouldn't be taken as the sole costs. I paid around $3,600 for everything, though all labor (except the machine work on the short block and cylinder head) was done by my friends and myself. Your best bet is to check the junkyard, online classifieds, online parts vendors, or eBay for various parts and accessories that you may need because you'll save a lot of money that way.

NOTES

(1): If you have a fetish and happen to like dirty underwear, then that's your business. Still, that doesn't mean you should buy used head gaskets for your car.

(2): The part number ending in 849 is for the upper and the number ending in 850 is for the lower. Both are standard sized.

(3): The part number ending in 002 is for the automatic transmission while 003 is for the manual transmission. I don't know what the difference is.

(4): I don't recommend buying used custom-made pistons because of varying tolerances and specifications. Even the pistons that I ordered from JE were the wrong size and I had to send them back and have another set made.

(5): If your car has the older style hex headbolts, replace them with the torx because the hex bolts do not expand at high temperatures.

(6): Any ECU with the Bosch number 0-261-200-173, 0-261-200-380, 0-261-200-524, or 0-261-200-525 will work. The ECU 0-261-200-153 is Motronic 1.1 and will also work, but is known for its problematic idle and therefore isn't recommended.

(7): There are many wiring harnesses available: The ones for the 87, 88, and 89-91 all have different part numbers but are more or less the same. The only main differences are at the fuel injector rail (I believe the earlier models connected directly to the injectors while the later ones had a seperate rail that connected the wiring harness to the injector rail) and oxygen sensor connections.

(8): The injectors from the E28 535i and the E36 325i/323i are upgrades to the E30 325i because of their higher flow rate. They are a direct bolt on and are recommended since the 325i injectors tend to lean out at high RPM. But be warned that your OBC AVG MPG and RANGE features may not be as accurate with the different injectors.

(9): Can also be used for the fuel pressure regulator o-ring as well.

(10): There are two idle control valves for the 325i, an L-shaped unit and a T-shaped unit. Both work fine and function the same.

(11): Throttle bodies from cars built after 1989 had dual vacuum lines that went to the brake booster. The ones before 89 had a single line.

(12): The oxygen sensor must be from the same year as the wiring harness. If the wiring harness is from a 91, then use a 91 O2 sensor. If it's from an 87, then use an 87 O2 sensor.

(13): The 325e's 80 amp alternator bolts right up, but you may want to use the "i" 90 amp alternator because it can handle the 325i's higher load.

(14): Use the cooling system and hoses from an '87 325i because everything changed in 1988. Unless you plan to over haul your entire cooling system to the later model (which is a useless conversion), use the parts from an 87.

(15): For cars made before 1/86 with a coding plug, use an 84-85 318i tachometer. For cars made 1/86 or later with a coding chip, use an 87-91 325i tachometer. For more information, click here.