I really like this thread....
Back in the day, I'd have to say Al Michalchuk. Al's homebuilt cars were always heavy, very basic, and almost always ran hand me down tires, and stock 283's in the sportsman. His modified (sedan & Gremlin) were powered by a 427 out of a Vette that he ran from '74 through '77. The old heavy car, and old tires were OK when it came to running sportsman, but by 1974, you needed a better mousetrap if you were going to have success in the modified division.
Al got in the McMann #4 Gremlin for the beginning of his rookie modified season in 1974 (same frame/engine that was on the sedan from the previous year, with the steering re-worked.) Al was only in the car for a few weeks and McMann pulled him. I'm not sure how good that car was at that point.... I don't think anyone won a feature with it from then on. (Craig McCaughey had a wins in the sedan version previously.) He was running top 5 late in the modified feature at Flemington when involved in somebody else's oil down, and had to get towed in. McMann pulled him that night.
Much later (1986?), Al drove Barry Schenck's back up #A (formerly driven by Rick Holden) but by then, there was a new way to get around Flemington, compared to the last time Al drove a modified in 1977. There wasn't nearly as much "turning right to go left..." I don't think Al liked the new way around.
Al told me that when he drove Barry's car for the very first time at Flemington, he went into turn 1 at speed (for the very first time with it), and almost clipped the inside boards.... because it was the first time he ever had a car that would actually turn to the left when you turned it to the left!
Still think that if Al had gotten into a top ride back in the day when the fast way around was still usually up high and a little sideways, I think he would of had success.