That's bad news John
I once had an MGB with a 289
A finish carpenter I know has a MGB with a 454 in it
When he ran it at the Track in Epping NH (way back when) at something like 12 seconds they got pissed and threw him off the track ,for not having the correct saftey gear or something, it was a street car, he could have been killed. Had pics in some hotrod magazine.
Tires were so wide and close together in the middle, when he laid rubba it looked ridiculous, almost one wide black mark.