I thought it was general knowledge that almost all side draft D-series throttle bodies were interchangeable but now after trying two different ones on our D15B7 this doesn't seem to be the case. We took another throttle body from an EG chassis D-series Civic and the throttle body from a D16A6 and neither of them would bolt up to the D15B7 manifold. I'm now extremely confused. Any input would be appreciated.