The 1st Gen. Lightnings were rollers....was it '93 they came out? Most 351 blocks afterwards were roller capable...but not all of them actually had roller lifters. Just like the first few years of the roller 302s. Also, they're a little bit lighter weight than regular 351w blocks....most likely due to some material being removed down near the main webs, pan rails, and cylinder walls (weaker block). Still good for 600+ reliable HP though.
