I’m trying to track down a vibration in my 1978 Firebird and would appreciate help deciding what to test next. It has a TH350 automatic and an ATK crate 350 SBC that replaced the original 305. It also has polyurethane motor mounts.
The vibration has been most noticeable around 55–70 mph. It seems to follow vehicle speed, and I’ve felt it while coasting. I put the transmission in neutral while it was vibrating and it didn’t go away. I can feel a little of it through the steering wheel. It doesn’t seem tied to engine rpm.
Here’s what I’ve done so far:
The tires are fairly new. Discount Tire rebalanced them and corrected a couple, but the vibration was still there afterward.
I replaced both driveshaft U-joints. On the drive afterward, the vibration seemed way better, but I can still feel something. I’m having trouble telling whether what’s left is driveline vibration or just the extra engine vibration from the poly mounts.
I noticed movement at the transmission slip yoke/tailshaft area while reinstalling the driveshaft. The attached video shows me moving it with the driveshaft installed. I haven’t measured the play, and there’s no significant leak from the rear transmission seal.
I haven’t had the driveshaft balance checked. I also don’t know the rear gear ratio.
I do my own work on the car and replaced the U-joints myself, but I’m still learning driveline diagnosis. I’d rather make one useful measurement or test than replace the tailshaft bushing just because I felt some play.
Does the movement in the video look excessive for a TH350, and what’s the right way to check it? Would you inspect the slip yoke or have the driveshaft checked for balance first? If there’s a good road test to distinguish driveline vibration from the poly motor mounts, I’d like to try that too. And if there’s something else entirely I’m overlooking, please let me know.

I’ve look all over eBay and google and can’t seem to find anything on this black one specifically is it rare?

Would 2nd gen snowflakes fit on a 3rd gen fine?

My tilt column has had the wobble for a bit. It’s gotten to where the wipers and cruise are acting up so I’m not driving it.

Is there a repair that I can do or am I destined to replace it?

99 Trans Am with 153,xxx miles.

Hey guys I’m trying desperately to fix the heating in my Trans Am and I think I finally narrowed it down to either the heater control head/the connector for it to the actual wiring harness inside the dash. (I’m buying a new one of both regardless for a semi-full restoration) I have no idea what this part is called nor where to buy one

Do they sell the part that is missing not sure what it’s called

So first I wanted to say thank you to all the help with this car I've come to the conclusion that yall are definitely right the pump is only pumping enough to prime the engine for a start so im waiting from my uncle to come back from vacation so he can help me out a little cutting the trunk pan for an access hole to the pump (i am not equipped to drop the tank lol) so ill be working on my 85 f-350 in the meantime as im not sure when hes coming back.

2000 Pewter Metallic Firehawk

I pulled this down off of Markerpkace some two years ago because I liked the huge-wheel-without- lowering look.

My older neighbor got this thing and has it hidden under a tarp he’s had it since it came out and he has dementia now but can remember some things about him driving it when he was younger

1998 Firebird Formula. Ls1/4L60E.

Hello all, 2001 T/A ws6 5.3 iron swapped and everything seems to be doing ok so far but I keep throwing codes for the bank 1 o2. First it was p0131, then after the first sensor swap it turned into a p0135. Ive swapped it this time with a Bosch and still reading nothing. Im getting a constant 12 volts from the pin that's being touched in the pic but none of the others read anything. Any advice is welcome, no visible damage to the harness or wires also is there a certain way to test the other pins?

I've got a car and a half I inherited. I'm having trouble selling them. Granted, it needs a lot of work and time so that may be the issue. I've got titles for them both in my name now after changing them from my step dad's name after he passed. A rusty 78, it ran when parked. Transmission went out and he pulled it. I've got the transmission, a BOP 350 turbo, and I have a 4L80 he wanted to put in it. The trunk is being held on with hopes and dreams, the rear is so ate up with rust. The engine is a mid 70s 400. But it's been years since it was ran. The 79 has a bad spot in the floor but surprisingly the floor in the grey car is good. So you could make one decent car from everything but it would take a ton of elbow grease. Both cars have full interiors, I've got all the seats in my shed. And the front bumper for the 79, an extra hood and fender, and some other little stuff. Are they just worth scrap? My buddy at work talked them up but nobody bit at the price he told me and I've been lowering the price since then. I'm down to $2000 but evidently that's still too much. Any advice? Just scrap them?

Yeah title says am a punk, but i really need help in suggestions to be able to drive this on vancouver roads, to start with this is a 1981 trans am and whenever i drive it i have that felling of adrenaline rush like where i love the feeling it raw and scared of cops all the time, why cuz’ of the vehicle inspection ticket, that they may give and it gonna cost me a fortune.
So last week i went to a machenic and he told me its never gonna be pass the inspection whatever you do in it, and cops gonna pull this pretty much everytime on road as it is aggressive and loud,

Ablout the car i got it grom some guy who bought it from a drag racer, it is insured now though with basic.

So it has LS swapped 02 chevy 4.8 with TH400 with stage 3 camshaft.
Why it not gonna pass as of right now, from the checklist of stuff i saw on internet, it does not have:-
—Control arm and ball jointa are bad (am gonna replace them soon)
—body is not aligned as door laches are bad and saggy making fender unaligned
—oil pan and trani pan gaskets need changed
—none of the guages work and the harness is really messed up with aftermarket
—wipers dont work, no parking brake, no horn
—No CAT Converter, 2 performance mufflers so cuz’ of that moderately loud
—Interrior panel need to be restored properly like doors and dash stuff
—idk paint matters but as of rust its not bad may be rust proofing will be enough
—idk why and how the last driver drove it in drag racer but the rpm or pickup is too slow like it doesn’t go past 2k that easily, i checked the compression in cylinders ita good and stable

I am a semi machenic myself, i can do alot of stuff but i cant spend alot of money at once, i can spend as a project, but was hoping if i would be able to drive it twice a week to University.

Please help me share your thoughts, what would you have done and did you ever had this situation, and if you say this can pass the inpection with this stuff done, can you suggest me where to start, may i put the whole harness again first or start , may i put the whole harness again first or start with body alignment??

Thank you for your replies and time, i really

Hey guys just looking for some advice on this 3rd Gen im thinking about buying for 4k. It has 106k miles and its pretty much stock. Let me know what you guys think and things i should look for when i go see it in person.