Just wonder what the max. safe bore is for 4.8/5.3 blocks, Im wanting to do 4" bore so i can use L92 heads/intake. I know its safe to go 3.90, but I heard they can be taken to 4", wanted to see if any body had done it, if not then how much they can take without reliability issues. I will be running about 17lbs boost and 175 wet shot and dont want to split a cylinder wall. I got an extra 4.8/5.3 block in the garage and would like to use it instead of finding a 6.0 block. Appreciate any help on this

 

You would be better off with a 6.0 block. Even if you found a 5.3 block that you could bore to 4.0 the cylinder walls would be to thin for that much boost and spray.

 

If you plan on spending that much money for "17 lbs of boost and 175 shot", then you can afford to buy a 6.0 block for $600 brand new. You could probably pick one up from a junkyard for cheap.

No way in hell you are boring a 5.3 to 4".

 

Well said

Bill

 

i didnt think it could go that far and be reliable, i had read an article where they had done it, but all i seen was some motor dyno testing, they never actually put it in a truck and thrashed on it. and it wasnt boosted. right now im running a whipple @ 7psi and a 100 wet shot, TR cam, worked 6.0 heads, stock LS1 shortblock w/ arp rod bolts. for next summer im wanting to go L92 topend, forged bottom, change crank pulley, and max out the NX solenoid. like you said iron 6.0 blocks are fairly cheap, almost cheaper to get a new one than to dig thru the junk then get the machine work done, just wondered if anybody had actually done it. thanks