Hi ; my 2.9 rocker assemblies need replacement is there anything with a 1.7 ratio available, . My engine has been making a nasty knocking sound , for years, but only occasionally, and only under power, .not like a rod knock, or a main brg or piston slap, and not really like lifter knock.( it scares the hell of people who ride with me , they're it's going to blow any second )I have not opened it up yet,I am hoping to find a new rocker assy, Is it possible to convert the heads to accept the 3.0 rockers? I've owned it since new, love how it drives and plan on keeping it until I'm too old to drive























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