I'm having a hard time choosing an engine, these are my issues: 1.I have a 1990 350 tbi, Id like to use my stock accessories including my TBI unit. 2. I want more power for towing. 3. Smog legal 4. MUST run on regular unleaded.(I drive in Baja alot) 5. Under 3 grand. Im considering a GM perormance engine, building my own, or dressing up a GM goodwrench engine. What are my options for combining tbi to one of these engines? Can tbi work with vortec or alum heads? thanks.