Bill Mitchell is one of those names ubiquitous to performance. He and his company, Bill Mitchell Products, are always thinking up ways to improve the performance of factory-style powerplants. This year at PRI, he’s showing off his second-generation aluminum blocks for Hemi and Wedge Mopar big-blocks.
“They are made out of 357-T6 aluminum with the standard 10.720 deck height,” Mitchell explains. “Each comes in either 4.250- or 4.500-inch bore, and those are the only options really. At some point, we’ll offer them in raised cam, again.”
The reason there aren’t many options is that the blocks come with pretty much every performance feature you could want, as standard. “The main caps are currently made out of ductile iron and were moving over to billet steel. The block comes with bronze lifter bushings, and the cylinder sleeves are made out of ductile iron,” Mitchell explains. “They take all stock accessories on the outside and have all the standard bolt holes.”
More than just a high-performance street block, these blocks are made to handle big power. We’ve got some guys who have been up near the 2,000-horsepower range already. A lot of guys have been using this block with power-adder applications. We recommend staying with the smaller bore so it’s got the most amount of strength, in that case, but the maximum recommended bore size is 4.560 [inches]. Some guys go a little bigger, but we recommend to stay in that 4.560 [-inch] range,” Mitchell says.
With some blocks already in the wild, there is a significant backlog already. “We’re just starting to fill backorders on these and we’re about 120 days out on new orders today,” Mitchell says. So if you’re on the fence, probably best to act sooner rather than later.