Me too! Just replaced my '89 Toyota pickup 4-banger radiator. Thought I'd be cool and use the factory clamps instaed of the old corroded worm-drive screwdriver install clamps. The idea is constant tension which can accomodate swelling and shrinking with temperature. Tried using channelocks, but no go, even on top where I could get to it easily. I gave up and put the old clamps on. Man those Toyota clamps got some tension. I think it would be hard enough even with the special tool.