After-Market frustration

[FLcustom10]

OK Guys, I'm not a mechanic and realize I'm in over my head. Working on this truck is educational and fun, but I'm getting really frustrated with finding parts that just don't fit. Do the manufacturers not test them before they sell them??? Here are 3 examples just off the top of my head:

1) Firewall insulation. The clips that they sent were way too big to fit in the holes. I hammered until I broke the clip thinking that I must be doing something wrong. I wound up going to Lowes and finding clips that would fit.

2) Something as simple as the ACC-OFF-ON-START label. I put it in boiling water trying to make the clips fit. I pressed until I put noticeable stress marks on it before I realized that I should just shave the clips down to fit. I used a black sharpie to disquise the stress marks.

3) The shift lever will simply not fit in the hole for it on the steering column. Luckily I have a used one that will work, but I already have a new knob for the after market one coming in the mail that will be useless.

I'm just ranting, but I guess my lesson learned is I will stop expecting parts to fit and will start shaving clips down before I try to force them.