UH'OH, here we go again,
I've got a 509 blk. 377"in my Malibu with 5.43 gears. When i first built it i put it in an 1850 dragster, it ran 5.15 and 8.23@158mph. I pulled the chip out and it was close to 8,000 rpm. It had a (4" long crack about 3/4" below the deck) and wouldn't hold water (we ran it dry) I then pulled it out and without pulling the heads, useing nirod i tig welded up the crack and then installed it in my Malibu. It's got 50/100 passes on it and if i run the qtr. mi. i pull the chip out and let it run, most of the time around 7800 rpm. Would i recommend this heck no, but it worked for me. I also have a 511, 4 blt blk that i'm building for a prostreet truck. But truth be known, i would go with an after market blk if i could afford it, because i'm sure i'm danceing on ice.
Zip.