I use my Chinese floor model drill press as an arbor press to assemble oil coolers, have done several now. If it isn't going smoothly, alignment is usually the problem. Just did my 7.3 PSD and it went smoothly. Really doesn't take THAT much pressure and it kind of ooozzzes into place smoothly. Can't imagine needing a floor jack. Oh and if the temp isn't really warm, use a heat gun to warm up the the bundle and the header. Helps.