You want to stay in a safe enough compression ratio so if you had a methanol system failure your motor does not blow. We have 9 second big block cars running the kits with high compression motors on pump gas. What ever compression ratio you can run with 104 octane you can run with alcohol injection. You can actually run more with the methanol because of the lower intake temps and EGT's.
50gph seems way to much for any 5.7 TPI motor maybe that's a type O. But unless your making 1000hp your not going to need that much.
Play with our nozzle size calculator to get close you your required nozzle size. Since your N/A a M14 would be about the MAX you would need. Our
Progressive Controller is also a good option for a N/A motor.