Whats big lift? As mentioned 55 and 60MM are pretty common. If it is a wedge much harder to come by at times. Hemi/Predator stuff much asier to find as the blown alky guys use the bigger cores. IMO most any cam selection over .800 will greatly benefit from a larger than stock core, there is a surprising amount of flex with BIG lift cams and the normal big lift springs they require. Getting the block machined would be your next issues. But Weston Machine can handle it and do it right and he's in NJ so not that far away for you.
100% Al, couldn't agree more. FWIW I just finished a block that i had 55mm cam core done with needle bearings. I had bullet make me a 55mm cam and we used a jessel key way lifter that uses a bushing instead of needle bearings. after it was machine, there was a couple places that had less the .200 of material left.
