back in the day, "customizing" meant: big block, small block or long block; relative merits of this camshaft over that; comparisons of gear ratios in transmissions and/or differentials; to hone out the cylinders this much or that much; edlebrock or holly; glass pacs or not; will these headers fit or "where's my cutting torch?" ... and we did it all in the backyard! today, "customizing" means: low profile? spoilers? type of paint job? which speakers? which stereo?