The deep holes are the ones the blower bolts should go through down into the lower intake, that or possibly the two halfs of the core use bolts to hold them together, I've never had to split one before, but yeah I'm betting he used a paper gasket and rtv to hold it down or just rtv, on my own stuff I rtv it and it's a bitch to take back off, you can text me some pics of the holes your talking about if you want but I'm 99.99% it's just rtv holding l it down and your going to have to pry it pretty hard if he used a lot of it, I've gouged the lower intake pretty good taking off intercooler cores that were rtv'd down if you get lucky he used a gasket and just rtv on both sides of it and it will rip the paper gasket apart making it easier to take off but a lot more clean up