LS7 is a Good NA block, if Fresh, if beat on they have drop in Cast Iron Sleeve that crack or the aluminum between the sleeve Crack then they are hard has hell to repair,
LS7 can go to a 440CI, you can run a 4.125 Crank due to the longer sleeves, if you have a LS7 block you can run the Darton or LA sleeve and then make it more reliable, and then make it up to a 454CI
LS3 is a great block for doing a 416, They can be made into a 425, but with the longer stoke the piston come out even more and adds to more piston rock and this is harder on rings sleeves and bearings
Sleeved blocks the Best block is a ls2 block to sleeve or a 5.3 with a 4th digit serial number to sleeve, if sleeved can go to a 454 cI,
RHS block what we sell a RHS block for is cheaper than sleeving a block RHS can go to a NA 482CI safely.
Making a motor last in the sand, one big part is valvetrain and valvetrain Geo.
