I have a 86 irocz that stock had a 305 and i installed a 400. I have it tuned to run pretty good but today when i was reading today i found out that if you do a 305 to 350 swap u need to change the esc and knock sensor to one designed for a 350 car. But my problem is i have a 400 so what should i do in this situation? I cant seem to find any info on a 400 swap as far as esc and knock sensor. I believe i would be better off upgrading to the 350 parts vs keeping the 305 parts. I am just wondering what the 383 and 400 guys are doing to make it work.

 

I'm wondering the same thing 400 block with code 43 all day long. Wrong sensor?

If so which is the right one?

 

I believe the 400 is pre-computerized stuff - thus there is no knock sensor or ecm available. I would think 350 stuff would be better, but I'm no expert. TBI or TPI? Might try in one of those boards.