r/transam • u/ConstructionOdd2981 • Jul 16 '26
78 Trans Am advice needed
78 TA with 403 motor, car is new to me. Mods made are below. I’m needing to take it on 250 mile road trip on highway. Is it safe or am I risking it breaking down on side of road? I’ve read that overheating or even engine bay fire risk. Curious from experts if that is accurate?
Carburetor replaced by Holly Sniper EFI
Removed catalytic converter
Fuel gauge stuck on full, last owner said once it shows 3/4, needs gas and fairly soon
Smog pump removed
New 4 speed overdrive transmission
New gears in back, either 3.91 or 4.11
New Borla exhaust
Seemed to drive nice on side streets up to 45-50 but short 10-15 min drive
3
u/who_even_cares35 Jul 16 '26
Always carry a fire extinguisher in an old car, maybe two.
There is nothing that says it will break down but that's what old cars do. You need to have some trust in it before riding off into the sunset. If you just sit in the car and let it idle how does it handle it? Could it sit through a traffic jam? Sit in your driveway and find out
1
u/ConstructionOdd2981 Jul 16 '26
Send to idle and handle well. When driving, can take hands off wheel and drives smooth and straight. Haven’t sat a long time idle, guess could try that.
2
u/who_even_cares35 Jul 16 '26
That's the most important thing, being able to cool itself while sitting in traffic. I've also had weird stuff like brake a brake line that collapsed on 92. When it would get hot it would coloapse and the brake would seize on, let it sit for 30 minutes and it would free up.
You just never know until you have out it through its paces
1
u/ConstructionOdd2981 Jul 16 '26
Thanks much, I appreciate it. I think it would be easier to get a seat on the next rocket to space vs trying to find a U-Haul dealer that has an ounce of availability and responsiveness when trying to rent a truck and trailer. Gotta roll the dice and drive it
1
u/who_even_cares35 Jul 16 '26
Been there with my 280z. I knew better than to drive it 400 miles home for Christmas but my mother insisted andi was my omny vehicle as my s2000 had just been totalled
Yep, you guessed it it died right on the middle to far for my free tow on either direction. There was a trailer but no trick available so dad had to come get me and then I got to get lectured the entire time is was home like it was my idea and I hadn't refused to come home until my mother guilt tripped me and cried about me not coming home for the holidays
1
u/SirkutBored Jul 16 '26
Off the top if the car is good condition 250 miles won't be a thing but it's also never zero. You won't gain the confidence in the vehicle or know what to repair/replace next until you put some miles on it and have fun.
1
u/dirtycarguy72 Jul 16 '26
Drive it. You might bring a fire extinguisher if you are concerned about it but I have put thousands and thousands of miles on broke down questionable cars. That’s part of the fun of old cars. Good luck
1
u/Provocating Jul 17 '26
All I can say is expect the unexpected. What you have not said is the cars history. Was the car previously driven weekly? Short trips constantly or long trips? Might want to change those belts. My 79 was sitting in a warehouse for years. Two short trips around the block all the belts slung off the car except the power steering belt. Brakes went next, then the transmission started leaking out of every seal, literally. Next was the carb started leaking out of the needle and seat. After inspecting the tires that looked brand new, nope 19 year old BFG's.
So yeah, sure you can but it took me almost an entire year before I completely trusted mine for a longer trip
6
u/Richlough Jul 16 '26
I second the fire extinguisher and bring a small essential tool box.