<html><head><style type='text/css'>p { margin: 0; }</style></head><body><div style='font-family: Arial; font-size: 12pt; color: #000000'>I will vouch for the need for Zinc Additive. I lost the camshaft in my 36 Ford ( 468 Cid) It was a fresh build with a ton of money invested. Being in the business I have built hundreds of engines over the years and never had a problem. After the failure I contacted Comp. Cams which had built the camshaft and got this reply " No zinc additive, no warranty" . Zinc additive is needed in every engine unless you have roller tappets. I add it to Every engine I touch without exception. It was an expensive lesson.<br>Mike Sorensen<br></div></body></html>