I am mounting a T5 into my '48 AD. Have removed the stock trans cross member for ease of installation. It will slide back under the stock T5 2-bolt boss on the bottom, but with only 1/4" gap. I fully expect to clearance the cross member for a rubber mount. My question is how thick of a rear mount should I allow for? The stock S10 mount, which looks like 2-3", or is that much mount needed?