I do not have a stock speedo because I transplanted a LQ4 into my 86 monte. My question is..What do I have to change so the PCM sees the correct pulses per mile? I would assume the speedo calc and fine tune are for stock vehicles, right?

The 2 variables that are not stock are my rear axle ratio (4.10) and my rim.tire size (26.61" diameter I believe)

Please get back to me, Thanks.