Hi folks,
I'm new to the whole older car scene and so far have been loving it. I drive a 1994 C1500 and recently bought a 1991 Trans Am GTA. The rear hatch has some significant overbite which is where I believe the water leak is coming from and I plan to fix soon but while it is the summer, I am replacing the carpet due to it being old and having a significant ant problem from the previous owner leaving food in it 🤮.
I purchased a new carpet from RockAuto with the mass backing option and replaced the trunk carpet with ease. My question is, in the passenger area, I have been having a hard time getting it to sit right. It seems like there is way too much on the sides where the sill panels go, it has a bunch of slack in the middle over the transmission hump, and it doesn't quite seat right in the back where the trim piece under the speaker goes (not sure of the name, I apologize). Anyways, I've been struggling to find a solid guide on what cuts need to be made. I'm worried about cutting too much and ruining it. Is there a lot to remove? How much should it overhang on the floor panels? And how far do I push it up against the firewall behind the gas and brake pedal?
Sorry if this has been covered before, this is my first post. I'll try to upload some pictures tomorrow after work for a reference. Thank you!

 

I had the same issue but took my time and made the appropriate cuts. You end up cutting quite a bit off, especially on the sides and up under the dash. I still have a little excess over the trans hump but I was able to get it bunched under the center console and it is not noticeable once reinstalled.

 

I'm pretty sure RockAuto gets it's carpeting from stock interiors. I bought their carpeting sometime back for my 91 TA vert and have it laid out waiting for an opportunity to install it.

Here is a link to their videos and installation instructions. Perhaps this will help you.

https://www.stockinteriors.com/install

 

All of the automotive carpet distributors get it from ACC which is the only manufacturer.
Trimming is to be expected. Just remember that you can always trim more off, but you can't put it back on, so take your time and make conservative cuts...

 

So before installing the center console and trim its okay if it isn't super tight? I thought it had to look almost perfect and the trim would work out the loose areas but its sounding like I can leave a little more slack. For the sill panels under the doors (the part that says body by fisher) is the carpet supposed to come over the sharp area that they cover or just up along it? I'll try to take a picture I forgot to yesterday when I got off. Thank you

 

It helps to lay it out flat in the sun to heat it up and relax the backing. That will also help contour it to shape. Use a seamstresses chalk to mark the areas to cut. You'll end up taking it in and out of the car numerous times. Prepare to be sweaty.