When was your "back in the old days" ? I thought the 10.5 tires are kinda new and built for the 10.5 door car classes. When I raced my Nitro Jrfueler we ran 8" or 9" wide tires and rims in 1963-69, with smoking the tires for about half track, way different tires and tracks we have now. M/T 10.5 tires are designed to run 13-14" wide rims, to get more tread width. Keep in mind 10.5 tires are designed for 2500-3000+ lb door cars not for 1300-1600 FED. Now with that in mind my friend Craig Bourgeois won the 2015 Comp Elim championship with his B/ND [JF] FED running 29x10.5x15 MT on 12" wide wheels [ rules limit]. Criag ran some .987 sixty foot times, with his 4.88 gear and that short 29" tire, but keep in mind racing in Comp most of the time you don't run it 1320' [ finish line racing]. When he did run it closer to the finish line , he was at 10,600 rpm.
Craig likes the stiffer side walls , again 10.5 made for heavier door cars, so he has less tire shake. His 10.5 is a 10.5 "S" I think for stiff, and MT also makes a 10.5"W" for wide, like 11" wide tread.
I have tested some 33x10.5Wx15 with a 5.14 gear, and don't shake, but I still ran better ET's with the 31x12x15 Goodyear. I plan on testing more at the Div 7 race in Sonoma. The plan is to try different tire pressures , last time testing was at 7lbs, different launch RPM, and maybe a different converter.
We mostly just race the NHRA Heritage series with limited Q runs [ 1-2] but we get at least 4-5 runs , icluding at least E-1, at the Div 7 race.
Again MT recomends at least 13" rims on the 10.5 tires, and I ran them on my 12" rims because of the JF , and B/ND rim limits.
I hope this helps ,
Jon