Correct, mine are drilled for an LA intake. You do have to use all other Magnum stuff, but the advantages are: 1) It's all available in the wrecking yards for cheap AND the rockers are 1.6 vs 1.5. Here's another interesting tid bit: The V10 rocker bolts up (same geometry) but the ratio is 1.7...we'll be using those if we run these on my 408 street/stripper. Word of caution, just like the OEM heads, the guides will only allow about a .530 gross lift at the valve, so any bigger requires trimming. That is easy to do, even for the home builder. Also, the Mag rockers oil through the pushrods, so you need the appropriate pieces there, including the correct lifters, which 99% of aftermarkets are for a hydraulic stick.