If I understand what you are looking for WQ, it may not find it on the web. Starting grids for races in the 50's and early 60's are hard to come by.
General info along the lines you mentioned.
The top dog car for speed in NASCAR in 1959 and 1960 was the Pontiac. Hands down.
1959 - - Fireball Roberts had the pole for the July Daytona race at 144.997 MPH, he also won the race at a 140.581 average. In the February events of that year, Fireball had the pole for the 100 mile qualifier at 140.580. A gentleman by the name of Bob Welborn won that race and the pole for the 500 in a Chevy. The 500 mile race was won by Lee Petty in an Oldsmobile.
1960 - - Top qualifying speeds in February were all Pontiacs. For two 100 milers and the 500 the pole sitters were Cotton Owens at 149.892 and Jack Smith at 148.157. Fireball won the first 100 miler in his Poncho and Jack Smith won the second in his. Junior Johnson won the 500 in his Chevy at an average of 124.740. In July Jack Smith put his Pontiac on the pole at 152.129 and won the race as well at an average of 146.842.
During those two years the only other NASCAR tracks which would be of interest in terms of speed were Darlington, Atlanta, and Charlotte.
Atlanta held its first two races in 1960. Fireball won both poles one at 133.129 and one at 134.596. He also won the first race. All Pontiacs. Bobby Johns won the second race in another Pontiac.
Charlotte also ran its first two races in 1960, and surprise surprise, Fireball won both of those poles as well. One at 133.904 and the other at 133.465. Joe Lee Johnson won the first race in a Chevy and Speedy Thompson the second in a Wood Bros Ford.
Darlington held one race in 1959 and lo and behold the pole winner was Fireball Roberts at 123.734, the race was won by Jim Reed in a Chevy. 1960 and they ran Darlington twice. Guess who won both poles. Fireball again at 127.750 in May and 125.549 for the Labor Day race. Joe Weatherly won the first race in a Holman Moody Ford and Buck Baker the second in a Pontiac owned by the aforementioned Jack Smith.