suggestions to make my stock 85 faster
#21
The L98 powered C4 will NEVER feel like you're driving your 700hp Cobra! But once you replace the injectors, it will certainly have more performance than it had. I wouldn't mod nothing until you do this. Personally, given that it's your Dad's car, sentimental reasons, etc, I wouldn't do anything else to it, except minor mods. Sure you can make an L98 go fast, it just takes $$$, time and trouble and by the time you're done, you coulda had a late C4 with the LT1 and significantly more horsepower. We own both, so I know.
Before you throw mods at it, check the basics. If the compression is OK, check the fuel pressure. Is it misfiring? When was it last tuned? Cap, rotor, plugs, wires, air and fuel filters. If all that's good then replace the injectors. FIC's prices are really very reasonable.