In spite of Many others declare of the 20HP or more raise- on modified heads on your own, this is solely unattainable without camshaft or pistons changed. Toyota has casted and machined all their 4 valve heads to very close and accurate tolerances for Avenue (and rally) use. I had https://zioncxsnc.qowap.com/86362765/a-review-of-4age-20v-itb