if i take a computer out of a 350 and put in my 305 will it ran better or worse shouldnt it give it more power im sure someone in here has tried it so i figured i would ask here before doing it thanks for any help

 

No advantage at all...most likely the actual computer is the same anyways, but the chip to control is different and not tuned to your 305.

Best bet would be to try the aftermarket custom chip programmers, or head over to the DIY PROM Board and learn to burn your own.

 

Mike is correct, as usual. There is no difference in the ECM between 305s and 350s in specific model years.

1987-89, both used the 1227165 MAF ECM and
1990-92, both used the 1227730 SD ECM.

As Mike said, the differences between the 305s and 350s lies in the eprom (though with SD cars, there is also a difference in the knock sensors with the Memcal).

With MAF cars, the primary difference in the eproms is in the injector size and spark advance curve. With SD cars, the primary differences in the eproms is in the injector size, cylinder volume and spark advance. Also, some had speed limiters and others did not.

 

Ditto