I was wondering if you could have used an earlier bellhousing from a setup that was using a 3 speed trans instead of the SM465 and then I don't think you would have to use the adapter plate. I installed the T5 in my '65 Pickup a few years back and I don't recall any problem with the retainer dimension but the '65 bell is a cast iron unit with the mounts on it. Excellent article and detail on how you did the install. Will be of help to somebody looking to do it. Are you happy with the new trans? I really like mine behind a stock 292.
