Heya guys back again with another question about the 350 swap i did not to long ago. I was wondering how important getting a 350 prom in the ECM was with my mild build--> 350, 202 heads, rv cam, hooker headers, and stock 305 intake with 22 injectors instead of the 19's.. i guess what im really asking is after getting the new knock sensor, ESC module, and 22 injectors how nessesary is it to get a chip.. and how much of a difference will it really make with such a mild build? thnx again guys!