This is correct the 0044 block is in my car now, and it has been great up to 550HP with not girddle, i have'nt been able to turn the boost up pass 20psi because the 2004R cant take it. I researched this engine alot before i tried it, and what i saw is they said they would crack in the lifter valley, but i saw that they all drilled a hole in there block for the oil return. That to me was the reson for the cracks, so i didnt drill a hole, i ran the oil return back to the hole where the manual fuel pump would have gone, and this engine is nothing short of amazing. If you do a search on (who's running 4.1's )you will see alot of info on my build, i just got a 291 block, and im planning to install a stroker, when ever cash come's available. The other caddy engine that dont work is the 4100(V8), not 4.1. Also if you are planning to run a roller cam, you need to change the front cam bearing, TA perf sell them, that is to allow oil to the driver side lifters.