How should I go about adding horsepower to my 1987 Blazer with a TBI 350? It seems like there is no way to get any good power from it. It has 35" tires with 4.10 gears. It has hooker headers and 3" dual exhaust and turbo packs. The heads were shaved and the compression is up to 165 psi. Basically everything else is stock. I was thinking a mild cam would help and possibly upgrading the computer. What are your opinions? It seems that I had more power before I started to add things. The reason I am asking is I and torn between getting a big block and modify it mildly or keep the 350 TBI and modify it. I Want to save my good gas mileage because I tow car haulers and camping trailers!!