I have turned up 15 or 20 89-93's by turning in the load screw. The idle will slightly rise and you will have to back it down. One turn gives you a lot so it is trial and aer. You should install a bust guage. If it is over 26 or so psi back the screw out a little. You can also run down the afc screw to get fuel to come on sooner. I have yet to see any drive line problems when keeped under 27 psi. I get 35 psi. but I am carefull ( how long,how warm the engine,what gear,ect) I don't recomend any else thy that it caust me a head gasket a countershaft bearing a inj. pump bushing.