I recently purchased the spin-on adapter plate from Mancini Racing to get rid of the 90 degree oil filter setup on my 340 LA. It is a six hole plate that is supposed to mount in the block, but it stands out about 1/4" from the mounting surface on the block. I talked with Mancini's about this, and they indicated to me that no such problems have been encountered with their product. They said the plate is specifically manufactured for them. Everything I have read indicates the six hole is for a Magnum engine, and the four hole plate is for the LA engines. My engine is a very early production (6/67 casting date), but the LA was around much earlier. Is that a potential issue here? I don't have a four hole plate to compare items. The attached photo shows my problem. Any suggestions will be appreciated. Thanks.