Gotcha. I used the round core they sell but it was just under $200 when I bought it last year. Since I already had the fan and motor, it made the most sense.

Is the square core itself replaceable in the future with an off the shelf design or is that a proprietary thing?

1950 Chevrolet 3100 (Ol' Roy)

1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)