Despite Some others claim of the 20HP or even more improve- on modified heads by itself, this is solely unachievable with no camshaft or pistons changed. Toyota has casted and machined all their 4 valve heads to quite shut and correct tolerances for street (and rally) use. Exceptional company all https://4age20vturboengineforsale73715.tribunablog.com/the-best-side-of-blacktop-4age-40933517