Cutlass bumper trim ?

[69hurstolds]

SOOOOoooooo....I think we can finally get something that may end the confusion here.

I had a small piece of factory-installed bumper molding in a box of small parts in the shop.

My calipers measure it out at 0.3205" nominal width. Thusly, it's ever so slightly wider by 0.008 inches than 5/16" (0.3125"), but a far cry from 3/8" (0.375"). In metric terms, the 0.3205" is still just a "C" HAIR over 8 mm.

It is my estimation by the actual measurement the correct size you would need to buy is 5/16" (8mm) width. I say that because the NOS GM stuff is hard as heck to find. Almost unobtanium. Next time I dig out the NOS ones, I'll measure those to see what they tell me.

Incredulous that I've never measured them before. I guess because I never needed to. Hmmm.

I can't seem to find any aftermarket ones that are 5/16" wide. Anyone?

 

[maxi426]

J&J Auto Fabrics is where I got mine. Can't remember how I ended up there. I Know I would have insisted on 3M attachment tape, and theirs had it.

 

[69hurstolds]

Welllllllll........

I just ran across some NOS stuff I had in a box. Word to the wise. DO NOT hold on to this stuff for 25+ years. The way it was curled allowed the chrome mylar to separate. Totally useless now. At least this piece.

It is crowned in the middle. And with the calipers, it appears to be nominally around 0.3565" wide.

3/8" is 0.375", and 5/16" is 0.3125", so it lands in the middle. Closer to 3/8" than 5/16". I'd still go with the 5/16". It's only a 0.040" spark plug gap away.

Here's the caliper measurement

And here's the cross sectional view

 

[69hurstolds]

Let me add some stuff here I found out this evening.

For whatever reason, I was digging out an NOS power antenna to do a metal cable conversion on, and ran across some COWLES 37-630. 3/8" x 20' per box. I got 2 boxes. I didn't even know I had these. I can't even remember getting these.

The Cowles website says its 3/8" wide. If it were, it might be a skosh too wide for the gap and there may be fitment issues. Some have had this with other brands of trim.

SO...for funsies...I measured the width of these bad boys.

0.3325" How is this possible? I didn't take any proof of life pictures (I may tomorrow), but I measured it a bunch of times to verify it. But it is NOT 3/8" wide (0.375"). It's a spark plug gap width narrower than an actual 3/8", and with the NOS GM stuff at 0.03565, it's only like 24 thousandths narrower than the GM part. So it should fit without issue and not look too narrow. Only reason I can think of it wouldn't, is if somehow your bumper cover got sun-warped or something to narrow that gap.

Another slight difference I found to GM stuff is that the Cowles stuff is a bit more rounded than the GM stuff in the middle. There's a more noticeable peak on the GM part. But, without a good source, the Cowles should serve the purpose well.

Anyway,

Just thought I'd throw that out there.

COWLES 37-630. 3/8" x 20'.
COWLES 37-650. 3/8" x 50'.

$28.99 and $43.99 from the Cowles website. Enter "COWLES" at checkout and save 10%. So for <$40 you can get a 50 foot roll of it. Not bad.

Has a blue translucent protective peel off cover and 3M double faced tape to hold it to the car.

As far as black, they have that too. You can paint that to match your car if you like, for example, having a Hurst/Olds, you would want to paint it gloss black for 83 (raw it doesn't look gloss black, more satin black- needs to match the body color), and silver for the 84. You could paint the chrome version as well, but if a rock chipped it, chrome would peek through perhaps. Anyway, here's the numbers for that.

COWLES 37-631 for 3/8" x 20'. For the 50' version, it's 37-651.

$28.99 and $40.99 from the Cowles website.

 

[69hurstolds]

Here's some pics.

Here's the shape of the end. Compare that with the GM which has a "peak" of sorts.

3M tape

MMMMMmmmm.....shiny.

 

[oldsofb]

You could probably clear coat the Black to get the gloss I would think.

Hutch

 

[69hurstolds]

You could probably clear coat the Black to get the gloss I would think.

Hutch

Perhaps. The concern I'd have with that is would the shade/intensity of the black with clear be correct? I dunno. Maybe. It would need experimentation. Not all black shades are created equal. I would find it just as easy to install the black trim before prime and paint and do it all at once.