4.3 to 350 chip question hypertech??

I just swaped out my 4.3 for a 5.7 in my 93 c1500and have been having a hard time finding a chip for a 350 from a 93 in the local yards. I decided to purchase a chip from hypertech. I thought it would be a direct replacement as was the superchip i used in a previous swap, but was wrong. The chip has to be used with the factory chip installed to it. Will this run my motor correctly with the 4.3's chip. I would assume so, because the hypertech is for the 350 and is supposed to controll the engine and trany, but want to make sure, so that I dont have problems when I go to start her up. Thanks, Jay

Did you change the ECM too? You should check the PN on the 4.3's ECM. Some of the late 80's and early 90's ECM's were not the same for the different engine sizes.