I have the typical ls/vtec setup going on. The block is going to get sent out for sleeving, but im undecided on a bore size and have yet to get pistons. Is there any real difference vs spool times or power gains from slightly increasing the bore size? I do not want to go to 84mm in fear of having a issue with the motor and making the sleeves thinner on the next rebuild/ re-bore. Would there be any gain at all to increase to a 82mm or around there from the 81mm stock?

 

more displacement is always good especially if you're trying to spool a relatively big turbo. 82mm or 83mm is good if you want room for future overbores.