That makes me wonder. Because i have a 68 318 with 273 crank. And what i can see on my order history is that the mainbearings iwe used is supported for a 74-up 318.
But the crank hade been grounded .10
Iwe ran the motor for a short while, then sold the car.
Maybe i have to check over the bearings then.
Could be because of the fact that the early thrust works in a later block...so its supported '74 - up usage. Really.. the only catch is you cant fit a later model thrust into an early block that is machined for the small thust bearing.
