Stuff you cant stand under hood
 

I cant stand when people leave radiator hoses stickers on them,its really a turn off on a clean engine bay.
Also yellow spark plugs wires and one more fake chrome wire loom.
Whats yours?
Oh one more part no. stickers on exhaust.

I like yellow plug wires if your going for a ‘day 2’ look.

I can’t stand color/chrome loom, color zip ties, senseless stickers, the motor and fender wells both painted the same glossy color as the car (usually red).

oh and the valve covers with fake rivets/bolts.

Lever style Radiator caps, temporary battery terminals, top cog belts, flexible universal radiator hoses, wrong hose clamps, cheap batteries, chrome fuel pumps, cheap braided hose coverings, flex fans.

Glass fuel filters.

Most aftermarket air cleaners.... especially the fly-eye Edelbrock bug catcher

For me it's billet anything.

LSx.....unless the car came with one originally.

Plastic or glass fuel filters should only be used as a temporary crutch to diagnose a problem.
Corrugated plastic hose covers are goofy.
Lever radiator caps serve a purpose, many things worse than cogged belts.
Plug wires zip tied together are a problem down the road.
Bungee cords for battery hold downs...seen someone do that recently...LOL..battery somehow got into the fan....
Rubber hose from fuel pump to carb...

I don’t mind the glass filters. I like to have that sight glass to see that fuel is flowing. I don’t count on it’s filteration properties.

I don’t like seeing an sbc under a Pontiac hood. I can tolerate a gen 3+ swap. At least your going forward then. Not sideways. I suppose that’s an obvious answer though.

I also don’t like seeing Edelbrock carbs in supposed high performance applications for the most part.

sbc in anything that’s not a Chevy.

I have lost interest in so many Pontiacs at car shows for this very reason. Two years ago in Myrtle Beach I saw an absolutely stunning copper colored 66 Tempest from the rear and started making my way over to it. Exterior was flawless perfect wheels perfect stance perfect interior it was just a beautiful car. The hood was closed so I asked the owner if I could see the engine expecting the same level of detail. The detail was there alright.....on a BBC. I just said thank you and walked away. Also I don’t care for the LS conversions either but they are marginally better.

I can't believe you guys didn't mention the red Buick air cleaner decals that say '400 4V' or '455 4V' that Pontiac never put on their air cleaners.
I hate those twist off valve cover handles that I guess people used on solid lifter engines so they could get the covers off quick but not many people run solids.
I also hate seeing a Chevy under the hood of a Pontiac. I hate seeing 'restored' cars for sale that are missing their air conditioning compressors.

Being that you didn't keep it Pontiac specific; the number one thing that bugs me under the hood is when the motor centerline is foward of the front axle centerline - hahaha!

Other than that, it's those hilborn or bug catcher type scoops on a 4-barrel - the ones that belong on a supercharger or something serious. Too much chrome and polish gets to me too. I also hate colored wire looms, and those large billet wire holders.

Sometimes people just want to buy every $25 fancy parts store chrome bit they can buy. I don't like that either. Sometimes they do it on the outside too - they'll have small trucks with bug shields, fender markers, a visor, yellow cab lights, tinted windows, plastic running boards, decals, a spoiler, a bed cover, an aero cab attachment, and every cheap tack-on, add-on part they could buy all crammed on the same vehicle.

Oh, and my absolute favorite; a home wire nut!

On a 60s era anything (GM, FoMoCo, Mopar, AMC, any of them) I can't stand anything other than the way it rolled out of the assembly plant. You guys named most of it above.

MSD box slapped right on the inner fender, carrying a color theme from the body into the engine compartment - i.e. colored corrugated wire covers, air cleaners, etc., model car or stuffed animal perched on the air cleaner

Ford "CAUTION FAN" stickers on anything but a Ford. Ugh.

And those modern red and white plastic caution tags on the repro battery terminal that everyone thinks has to remain there to look vintage. For some reason they believe that have to stay ...like a mattress tag that cannot be removed under penalty of law!

If it's not my car why should anything on it bother me?

Glass fuel filters. They come unscrewed easily or bang against metal and bust.
Engine blocks painted florescent green or yellow.

Led lights to light up engine bay.

X2, to each his/her own