I just installed 191's this past weekend... i like the extra 40 horse or so they put down... i took the stock ones out
and they have th number #'167' on them. . their out of a 160 truck... i want to have them Lathe cut WAYY beyond the 191 flow rate?? can anyone give me specs on how much to cut them and what part of the d'valve do you cut...
... how about running without delivery valves? 


