DIY pushrod kits are available from most mfg. (Comp, etc.) consisting of both ends and a length range. Select the ends based on your tappet and adjuster types, length slightly longer than you'll need. Make an adjustable out of an old one by splicing in a piece of 1/4-28 female threaded tube, and measure each one to give 1-2 threads. Cut the tube, and press the ends on.
Re: "This showed that my pushrods were too long by a bunch"
More details on the pattern?
