1999FirehawkLS1

iTrader: (21)

Just like the title says can a 6.0 iron block be bored and sleeved out to a 4.125 Bore, Does anyone know a company that will do this?

ERL only deals w newer Alum blocks w the window in it I think

Isolde

iTrader: (4)

Trying to bore an LQ4 block that far, the sleeves will have to be exposed to coolant. You'd have practically none of the original cylinder walls left.
If this is drag-race-only, you could to a tall fill with block filler, then just bore it to 4.125", forget sleeves entirely.
If you want the sleeves not exposed to the water jackets, then there's no point in using the sleeves.
4.060" is safe. You're only giving up 14 cubic inches at most, assuming a 4" stroke.
Otherwise, just start with an L92 / LS3 block, those can take a 4.125" bore in their stock sleeves.

1999FirehawkLS1

iTrader: (21)

I know that Im talking about boring it out to put bigger sleeves in it

KCS

iTrader: (20)

Steve @ RED covered this at least once already. You can sleeve an iron LQ4 block, but its more costly in the end than starting with an aluminum block, or even just buying a GMPP LSX block, since iron is harder and takes longer to machine.

1999FirehawkLS1

iTrader: (21)

Fail!!! lol just checkin I got a set of Ls7 heads was trying to use em cause they dont seem to be selling on here for some reason