Im building a GSR Block right now. And I was wondering what the best bore would be to do. Ive heard 84mm, and Ive heard 87mm... Which is the best? I plan on resleeving the block with Golden Eagle Sleeves also... Please help. Anybody help please...

 

87MM, lol. Whoever told you do take a GSR motor to 87 is a crackhead (I don't even think there's physically big enough bore spacing, let alone enough sleeve) or maybe they were thinking of the K20's which are 86MM stock. Anyways, for a turbo setup i'd go smaller, anywhere from 81-83MM still gives you enough room to rebuild if need be, and the power gains by upping the bore are negligable for a street car.