im just stating my experience . it cost me around 1000 bucks to have it all done and for the few ive done, theyve held up very well, most stay around 5 to 600 rwhp w/ the exception of 1 . i have a buddy w/ a dss 306 and strim, afr 185's , etc, he had them put the long block together w/ the heads, box stock , when he got it , they told him an anderson b41 would work w, no issues, POW bent valves doing his burnout in the box,im with you guys, if they dont know any better than that , they need to be washing cars not building engines. they also tried to tell him to throw 20 lbs. at it,, i talked him out of it. whew!!