custom chip for heads, cam and larger displacement motors such as 383 strokers or 496 in case of big blocks. I have this chip separately if your changing your own fuel pump and fuel pressure. For these chips, I need to know everything so I have a custom tuning form on my menu list for you to fill out and recommend you send that to me BEFORE ordering the chip. After doesn’t hurt either but want to make sure there isn’t an issue as your still limited to a level 6 camshaft just because of TBI. With the big blocks we can run a little more cam than the SBC by about 8 degrees of duration.