N need of tbi chip

[Fast355]

Block bored .30 over , valve lift int .420 exh .443, cam lift int .280 exh .295, duration int 204 exh 214, center line int 107 exh 117 LSA112 based on 1.5 RR, ill b using 1.6 RR, headers no cat , bbk underdrive pulleys, summit stage 1 sqare bore with adapter, ultimate TBI mods

I drove a TBI G20 van for nearly 6 months with a stock chip despite having a Mellings MTC1 cam, 14022601 53cc chamber 305 heads, and an Edelbrock performer RPM intake on it. I also had long tubes and full exhaust. I had the fuel pressure bumped to 14 psi and set the timing to about 8° BTDC. Ran and drove just fine on the stock chip after knocking out the minimum air rate screw cover on the throttle body and adjusting the idle to 650 rpm with the IAC forced closed and disconnected (Jumper A to B in the ALDL like you are checking codes, leave the key on for 30 seconds, and with the key on disconnect the IAC connector). I then reconnected the IAC and the ECM was never able to let the idle go under 600 rpm in drive. Ended up later tuning that setup as well as swapping in a F-car LT1 cam and ported 193s.