Ecm help

[John111276]

I have a 90 1500 with a 305 with a cracked head. I have a 93 with a 350 can I put the 350 in place of the 305 and be OK or do I have to swap computer and wires out also. Any help be appreciated as I need this vehicle to transport my son to and from school

 

[Breakdown]

Wiring should be the same. Ecru swap would probably be the best bet as long as the transmissions were the same model. I think you have a 700r4 vice a 4l60e so you should be ok. Heck you probably only need to swap the chip out of the ecu's

 

[kennythewelder]

The engine block is the same, but the 350 has a bigger bore. The heads are different. The chamber where the valves are is bigger in the 350. I am not 100% sure on this, but I think the ECM is the same on the engine controls, but the transmission controls will be different, The 93 has a 4L60E trans and you have a 700R4 I think. You always have the option of pulling off all of the TBI stuff, and installing an intake manifold with a carb, and a HEI distributor. LOL the same answer I gave you on gmtruckclub,com

 

[John111276]

Ok Im pretty sure it has a th400 in truck is that gonna effect anything?

 

[streetperf]

Ok Im pretty sure it has a th400 in truck is that gonna effect anything?

John, Kenny is correct unless someone has changed your trans. The trans for that truck is a 700R4. It should have a kickdown cable going to the TBI unit. 400's do not, they are electric.
If you install the 350, most of the sensors should be the same. If in doubt remove the sensors from the 305 and install them on the 350. You will probably have to change the injectors using the 350 injectors.
The swap is quite straight forward. Many have done this with very satisfactory results.
Good luck with the swap.

Mike