It can cause undue wear on your input shaft bearing. I have a Tremec TKO 600 on my 292. Warranty requires less than .005" runout. I used the offset pins with the set screw in the center that lock the dowel in place and make adjustment easy. I got it to .002" I think. The pins I bought were .007" offset. You order the size you need. https://www.summitracing.com/search...ord=Transmission%20offset%20dowel%20pins

Old enough to know better, too young to resist.