Yeesh! The 13G is just like the 20B. The main differences are the coolant seals in the rotor housings on the 13G vs in the side plates on a 20B. The cost is a lot different too as the 13G is a low volume production racing engine and the 20B is a luxury car engine with about 5000 units out there. Still low volume, but that's a lot more than the 13G's numbers.