as long as you keep your OBD0 cluster, you'll be fine. The speedo in USDM OBD0 cars is in the guage cluster, and is cable driven from the transmission. If your speedo worked when the car was OBD0, it will work with it OBD1.
As for vtec engaging - Crome uses the stock code, so vtec engaging will be like stock and will be affected by everything the stock code is affected by.
And please READ. Try to ask questions in the assistance forums NOT the development forums. There are no exceptions to this because you'll find that finding things here is hard enough without repetitive questions crowding threads describing work in progress.
