One such viable alterative that is readily available and easily modified is a heatercore. While there are many different models that can be modified to work in a watercooling system, one that has gained quite a following is the Chevrolet Chevette heatercore. More specifically, the heatercore for the 1986 Chevette, Fedco part number 2-161 or GDI part number 399069, which is approximately 6-1/8" x 6-3/8" x 2". The factory tubes are 3/4" and 5/8" which require some modification to work with 1/2" ID tubing used in a watercooling system but this modification is not that complicated and well worth it considering that most auto parts stores have this heatercore for around $22. Additionally, the tools needed for the modifications are fairly inexpensive and they are likely ones that most already have on hand.