Anybody here ever install the larger 2.0" intake valves(or LS1/LS6 heads with 2.0" intake valves) on a standard bore 4.8l or 5.3l? Gm claims the LS1/LS6 heads will not work on the 4.8/5.3 due to the bore bieng to small. Anyone with experience on this? Looking to have a set of 862 casting 5.3l heads gone through and would like to bump the intake valve to the 2.0". Are the valve angles different on the 5.3 heads from the LS1/6 maybe? Any insight would sure be appreciated. Thanks, Dave.