Last year was a hugely promising one for this young Liverpudlian who, at 6ft 2in and 12st, is as powerful as his name suggests. He began the season by setting an English Schools' 400 metres record of 46.30sec, bettering the mark set two years ago by Grindley, his training partner. Next came the European Junior Championships, where, like Roger Black in 1985, he took the 400m title with disdainful ease. He then became the youngest person - at 17 - to represent Britain in the World Championships, running honourably for a 4x400m relay squad which lacked all four of the men who had kicked US butt at the previous championships in Tokyo.
He is forthright about his targets this year. He is after Black's under-20's record of 45.36sec; if selected for the Europeans, he thinks he could get a medal; and he intends to indulge in a spot of his own US butt-kicking at the World Junior Championships in Lisbon.
'America has never lost the 400 metres at the world juniors,' he said. 'It's going to happen this year. They are going to be so shocked that it is going to go right through the senior ranks. I think we can win the relay, too. . .'
It is ebullience, rather than arrogance. Bullock, who was a good enough centre-forward to attend Liverpool's School of Excellence at Anfield, and a good enough rugby union winger to score 92 tries for his school and club in 1989-90, has an open mind and a desire to learn.
In Stuttgart, he and Darren Campbell, the sprinter for whom Linford Christie has predicted great things, spent half a day at a time at the warm-up track simply watching how the top men in their respective events prepared themselves. While Campbell concentrated on Christie, Andre Cason and Carl Lewis, Bullock was noting the activities of Butch Reynolds and the awesome Michael Johnson. 'I wanted to know what drills he was doing, and how long he would warm up for,' Bullock said. 'He was very focused. . .If you can't take experience from that there is something wrong with you.'
There is a suitable respect for the nation which has ruled one-lap running, but training with Grindley, who beat every American except Johnson last year, prevents that respect from turning into fear. As they pound the pavements around Wigan, or slog up Rivington Pike in the rain, the two Britons discuss how to beat their counterparts enjoying the Texan or Californian sun. Even Johnson is assessed. 'He has a move he makes after 200 metres,' Bullock said. 'If you can get far enough ahead of him by that point, then one day there will come a time when you will beat him.'
As Bullock acknowledges, that is more of an immediate concern for Grindley, the British record-holder with 44.47sec. But if the younger man's learning curve continues to rise as steeply as it did last year, it will not be long before he begins to run Grindley close, or even beat him.
Chris Butler, who coaches both men when he is not overseeing the fitness of Wigan's rugby league squad, believes Bullock has the natural ability to go as far, if not further, than Grindley. While Grindley has been weight training since the age of 15, Bullock has only started in earnest this winter. 'Obviously I've got bags of improvement to make there,' he said. 'My personal best is about 200lb, which is 60 or 70 off what David is doing. Once I get to that kind of weight, I'll be in the 44- second bracket.'
But if Bullock does start to beat Grindley, he does not think it would mean the end of their collaboration. He cites the continued partnerships of world-class American runners such as Danny Everett and Steve Lewis at 400m, or Leroy Burrell and Carl Lewis in the sprints, as encouraging evidence to the contrary. 'Success breeds success,' he said. 'Training with David has opened lots of doors for me.'
This year should see more doors being banged open by Bullock's broad shoulders. While he is at present in Florida for a fortnight's warm-weather training, it is the memory of recent, rain-lashed endurance runs which is more likely to sustain him. 'It makes you hungry,' he said. 'When you have done all that work, you are not going to let anyone beat you when they shouldn't do.' It will be fascinating to see anyone try.