Yup, that they did.
And thats part of the reason, after we did the modifications..we ended-up putting in new main-bearings.
We cammed it, then put on a lo-rise Edlebrock, new carb...he drove it a few days, then we spent some time trying jets...went a little smaller on the primarys, couple up for the secondarys.
We were goosing it pretty good. Then we spotted Craig's brother in his 1967 CobraJet....seemed like a good idea at the time to run 'em against each other...Cobra fell back 'till second, then pulled up...third-gear we were pulling ahead,
...but we heard a sickening sound....A Main Bearing spun!
Limped home gently, popped th' pan next day. The crankshaft was undamaged. So new bolts (Drilled for saftey-wire) and racing bearings, 'N me under the car trying to "Plasti-guage" the clearances, with nervous-Craig over my shoulder, lol.
(That took longer than it should've.)