7/16 Converter Bolt Length

So I bought a brand new FTI torque converter and a TCI SFI flexplate because of the need for 7/16-20 converter bolt holes. The TCI flexplate is .107” thick and the converter holes are threaded .700” deep. ARP converter bolts are .500” below the head... and are to be torqued to 60 or 70 foot pounds. The max engagement into the converter is only going to be .392” and at that much engagement and that much torque... it seems like not enough engagement. I was always told bolt engagement depth needs to be bolt diameter times 1.5 meaning on a 7/16 bolt it would be .656”, which the converter will support. However, the aftermarket bolts will not... what is everyone else using?