I have a 1986 Trans Am with 305tpi/700R4 and an ADS chip(original chip is MIA)

I'm building a 355 to swap in since the 305 is toast and I have some concerns about the fuel system:

1) Are the stock 305 injectors going to work with the 350?

2) Is the 305-calibrated chip going to work with the 350/stock injectors

3) What about 305 chip with 350 injectors?

4) I'm pretty sure that the stock PROM is 32B with 1227165 ECM. Does anybody know what the PROM for '86 350 is (guessing camaro since TA didn't have 350 that year)

 

Get bigger injectors(probably 24#) and get an new prom from a 350.

 

The 305 chip will usually work OK on a MILD 355 with an AFPR as long as the 305 injectors are used. Running a 305 chip (19# injector constant) and using 350 injectors (larger 22# injectors) will cause a rich condition. The chip and injectors need to match --- 305 chip with 305 injectors or,,,, 350 chip with 350 injectors.

Neither the Camaro or Firebird came with 350s in 86. However, if you go with 350 injectors,,, check the FAQ section of this board (link) for the PROM listings and pick the 1987 or 1988 350 chip that matches your gearing.

https://www.thirdgen.org/newdesign/faq/thirdgen.shtml

 

The best solution is to get a chip burned. The larger injectors will confuse the computer but it WILL be able to compensate in closed loop by using the other sensors (considering they are in good working order) and will be able to compensate. At WOT (power enrichment mode), you will run pig rich as the computer will rely on preset settings and not the sensors.

 

What about adjusting the injector# constant from 19# to the 2x# of a 350 injector if using 350 injectors?