there should be no problem that's like 62 mph...that motor is just getting warm...careful of the speed rating of your tires~
got the J-type overdrive?
Seeing as the '79 MGB has a top of about 93mph (around 150kph) that should not be a problem, just give the car a bit of a tune-up (filters, plugs, points, fluids, timing and mixture) and check the brakes before speeding off though.
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