Despite Many others declare of the 20HP or even more improve- on modified heads by itself, this is simply unachievable devoid of camshaft or pistons modified. Toyota has casted and machined all their four valve heads to extremely near and accurate tolerances for Avenue (and rally) use. I was gonna https://4a-geengineforsale51492.blog-a-story.com/6467224/about-4age-20v