Berg guides are produced from the highest strength and quality silicon aluminum bronze (127,000 PSI). This ensures maximum life, heat dissipation and proper sizing after you install them. Will not collapse or bend during installation when proper press fit is present. All are shortened at the spring/retainer end for more retainer clearance, allowing higher lift without interference. ID sizes are held to minimum size tolerances. Never install oversize guides without properly reaming the head hole. If too much press is used or if the hole is not straight or round the guide can distort and cause the valve to seize or experience premature wear. It will often push off center and make seat grinding almost impossible. Remember, lube the inside of the guide with oil when assembling the heads and valves. Never use any type of grease or assembly lube on the ID of a guide. Made in the USA. Again, lube the spring, valve and guide just before you start the engine. |