I went to ASE last winter to have my 2.3 liter engine fitted to my 1986 Ranger, year released, to overhaul.- 3 months later every ring was broken, I got in myself, ported and polished the air intake and the head added a good manifold.With 200lbs of starting pressure I wanted the little beast to "breathe!" This Glass pack does its job very well, not noisy but helps with my 30+ mpg and 120hp (11 to 1 CR) - I live 90 miles out of town and enjoy taking this little beast into town once a month for shopping to drive - thanks again to Revane for the best parts for each of my trucks and other ranch equipment