TA63

iTrader: (5)

Which aluminum 5.3 block is suitable for sleeving out to 4.125?

Burken01

iTrader: (88)

Dry sleeves?

Then the 08+ Gen IV 5.3 aluminum block

Block # 12571048

This is preferred to use for dry sleeved blocks due to it is a siamesed wall block, no coolant passage between the bores.

This is the strongest production GM block made!

Wet sleeves can be done on any block, however they are more expensive.

Steve - Race Eng

iTrader: (1)

I keep new 12571048 blocks in stock for dry sleeving. There are two other casting numbers that will work. If you find other than 12571048 make certain it has siameesed cylinder bores, no coolant slot between the bores for dry sleeving. There is one casting number that is Gen IV externally but Gen III internally with a coolant slot. All front drive 5.3 blocks have a coolant passage and can not be dry sleeved.

Steve

TA63

iTrader: (5)

Is casting number 12569513 good to go?

KiwiKid

My 400ci, 5.3 Ls #12571048 block is out to 4.185" using Darton's MID wet sleeves system, all supplied by Steve at Race Engines, its been a long haul, but its almost ready to go together. I just have to get the front of the machined to suit Jesel's belt drive and then we are good to go.

My biggest issue was finding somebody to bore the lifter bores out .904" for the Morel big wheel lifters. In the end I had to get a fixture jig made, so its been a very expensive excise, and now they have banned the car, FIA GT3 Mosler, from the New Zealand Endurance racing Championship to boot.