And another variable to add.... ...I just had a shaft made up this week for a road runner I'm working on...There's a few different syles of solid joints...Some are heat treated and some are'nt...FWIW...I used the spicer solids in past years...This time I went with the brute force heat treated..The shop claimed they were the best with a bigger diameter at the cap than the others and use them in all the serious drag pieces they make..