Quote: Jason did my 527 block before we moved here, the 518 street motor is not bushed. The 518 made 775 HP on Oregon pump gas with the same carb that the 527 made 845 HP on race gas, both with the same set of ported Indy 440-1 heads I have piched a roller lifter out(the old bracket Duster) when a valve spring broke and bent the pushrod, oil pressure went to zero, the 527 motor broke a Smith Bros pushrod on the dyno testing and both lifters came out, no oil pressure loss
IMO that's is the only real reason to do this assuming the stock bores aren't worn out.
I have piched a roller lifter out(the old bracket Duster) when a valve spring broke and bent the pushrod, oil pressure went to zero, the 527 motor broke a Smith Bros pushrod on the dyno testing and both lifters came out, no oil pressure loss 
