Gear drive

I was talked out of a gear drive buy my engine builder. Do yo know Grumpy Jenkens used a factory nylon over aluminum top gear to reduce recipricating weight. to increase Torque. Just thought I would bring that up. I will be installing a gear drive on my motor when its out this year if I can,. Crank and cam line bore position determines if they can be used. Some chains are loose because of this and shorter custom lengths are available. Also factory chain tensioners are used for this reason. Is there a way to adjust the gear lash on these gear drives.