i posted this for the engine builders etc! H series bearings have more clearance so the crank rides on alot more oil. ment for dry sumped engines. no use in a street going 4ag, unless it has been built as a race motor with the crank linished and radiased and everything measured and put together a few times so all the clearances are exact. unless you are an engine builder it is very very expenssive to do properly.
mick