I believe that I can shed some light on the performance aspect. I've been involved with NHRA Stock Eliminator for almost forty years and there are a few elements of setting a car up for S.E. that offer some insights. The rules that were in effect when Alan won the Championship were substantially more restrictive than those that apply today and the liberalization of rules back in about 1988 easily account for the difference between the early ET's in the 12.60 range and those of later times.
Among the important things to note about Alan's combination are the head/valve combination and the size of the carburetor for that particular motor. In the first place, there were huge differences between the size of the carburetor venturi/throttle bore sizes on the Rochester 2GV-7029115 for the 250 horsepower and the corresponding dimensions of the Rochester 2GV-7029101 found on the 210 horsepower 327. Everyone knows that it's bigger but not many people have actually calculated how much bigger. The intake manifold was correspondingly larger as well. Secondly, the 250/350 motor used the same head casting (441) and valve sizes (1.94/1.50) as the Quadrajet-equipped motor that was rated at 255 horsepower. Among S.E. racers, the 441 casting is widely regarded as being at least equal to the 041 commonly found on the higher compression 300 horsepower 350. Finally, Alan was restricted to not only stock lift but also stock duration/overlap and valve spring seat and open pressures in the early days (prior to 1988). Those rules favored the traditional wisdom that stick cars are faster than automatics with the same engine. The bottom line is that that particular 2-barrel combination possessed very few characteristics in common with the 327 and 307 engines of the same year and the difference in cubic inches was not the greatest of the differences.
Alan ran the car in NHRA Division One. One of his partners was Ed Bednaz. Other racers from that era were/are bordering on legendary status as well. Dave LeBrun, W.A. Lee, Bob Broadbent, Joe DeLorenzo, are only a few. The guys in that part of the country were blessed with geographical proximity to some of the best minds in the sport (not that they weren't among that group as well). Top-notch machine work, careful set-up, competitive environment, and the access to tracks such as Atco, Englishtown, Maple Grove, and others, especially in the springtime can all enhance already significant performance factors.
A final element was the talent of Alan Peters, himself. There are a few S.E. racers who have become legendary handlers of the four-speed combinations. Ed Bednaz, Bobby Warren, Jim Waldo, Kevin Helms, Jim Hughes, are just a few of the other examples. Alan is something of a legend in the sport. No one becomes World Champion, wins the All-Stars event three times, and wins five national events without having a little something extra going for him/her. I only met Alan once and I've never raced him but it's clear to me that Alan was capable of consistently getting the most out of his car.
Those are only a few thoughts regarding the 250 combination and it's potential. if you decide to try it, good luck.
c
