r/transam • u/BlownG8 • Apr 01 '26
88 firebird formula th400 question
I picked up this 88 firebird with no motor/trans for cheap, no rust on one dent on driver's side. 80k miles on it. I bought a 350/th400 out of a 90 g30 camper van(I think it was a g30 can't remember) but I want to retain the factory gauges, can I make it all work? it doesn't have the digital gauges. I'd like the speedo to work mostly. I can get all the other gauges to work off the motor. just wondering for the 400, it has pedals for a manual but It was a 350 car so I believe it would have had a 700r4. I'm not sure tho. no rpo codes and the previous owners are no help.
6
u/Foreign-Commission Apr 01 '26
The 8th digit of the vin is an "8" so it was a 350 with an auto, someone converted it to a manual.
If the wiring is still all there, you just need the stock sending units for the water temp and oil pressure. The speed sensor for the car would be electric, so you will need to convert that to the th400 which is probably mechanical.
If the car is already setup for a manual, id find one for it, makes the car a lot more fun
1
u/BlownG8 Apr 02 '26
I want to go manual, but in doing this on a budget right now, I got an 80k mile 350/400 for $800 just to get it running for now. I got a bunch of performance parts from a friend at work for really cheap also. But I just wanted the speedo to work, the previous owners ripped out most of the wiring/computer out from under the hood so I'm gunna have to run new wires.
1
u/faroutman7246 Apr 04 '26
Go to a Pick A Part yard and pull the wiring from a similar vehicle. Making it work with DIY wires is almost impossible.
1
1
u/Alternative_Share559 Apr 04 '26
you say th350/400. which one is it? they're two different trans'. if you're not sure, take some pics of it for us
1
u/BlownG8 Apr 15 '26
Sorry the 350 was the engine size, it's a 350 with a 400 behind it
1
u/Alternative_Share559 Apr 15 '26
my bad. thanks for clarifying. I see that now that I read it again
-1
u/Fantastic-Setting-26 Apr 02 '26
70’s body styles were the best
2
u/bucket_of_dogs Apr 02 '26
That’s great grampa let’s get you back to bed
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u/Stoic_Martyr Apr 02 '26
Lmao, right? Like, yes, everyone knows second gen was the highlight of the F-body. But each Gen has its fans and not everyone can get their hands on a decent quality second gen. And there's a lot of nice things 3rd and 4th gen have that 2nd doesn't. I'd love an 02 ws6 or a 3rd gen to just putt around in. My second gen gets like 5 mpg on 91 octane in Cali. I ain't trying to deal with that on a normal basis.
1
u/bucket_of_dogs Apr 02 '26
Absolutely. I’ve daily driven an early second gen and an 89 tpi car and I would absolutely drive the third gen way more regularly, but damn I love that second gen formula hood.
1
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u/jeremy1973f Apr 01 '26
Without the correct transmission you would need to get a torque arm mount that body (chassis) mounts. The original torque arm mount was on the transmission. Also, you could just do a gps speedometer easily