hey guys, wondering what i'm going to need to do to swap a early (70-73) 400 sbc into my 88 firebird with the 305 tbi. what i'm mostly wondering about is what kind of injection should i go with( i have a chance to get tpi but it'll cost, stay with the tbi, or go carbed), and how are my gauges and such going to play out with the earlier engine

also i think i'm going to use a turbo 400 tranny for a while till i can build a 700r4, and was wondering about what i'm going to need for the driveshaft and shifter, i really don't want to change the shifter if possible

 

I have a 400 in my camaro with tpi and a six speed. The tpi on it is the tpis big mouth runners and lower intake. I have the tpis tpi wiring harness and speed density computer. As far as a turbo 400 trans. You will need to get a different trans crossmember and a drive shaft out of an 82 or 83 with a th350. Not sure about shifter mod.

 

Welcome aboard (if you haven't been welcomed yet).

As grover indicates, TPI needs a bunch of help in order to support a 400. If you currently have TBI, you might be $s ahead to modify it instead. With a good-flowing carb intake, TBI adapter, 454 TB, and PROM tuning (assuming exhaust is up to the task), you can probably exceed the power capability of the high dollar aftermarket TPI equipment while reducing what you need to change. You'll get a lot more help in that area on the TBI forum.

The TH400 will require crossmember modifications, torque arm accomodations, and a longer driveshaft. I'm trying to recall a mental picture of the TH400 & TH700 pans for the bracket bolt-up likelihood, but I don't think you'll be able to bolt the bracket directly to the TH400. The shifter itself shouldn't be a problem. With all that is required to mount a TH400, I don't think I'd do it as a temporary system. Get the TH700 up to snuff up front - you'll probably spend as much putting the TH400 in as you would to get the TH700 built, and wouldn't be able to use the stuff that you had to buy for the TH400 on the TH700.

 

Oh, carb'd would certainly be the cheapest route to go - unless you have emissions considerations that would require some sort of certified EFI, in which case carb would be very, very expensive.

 

wow thanks for getting back to me guys, i used to own a turbo supra and those guys were dicks at those forums when i would ask questions.

yeah i'm from connecticut which is pretty strict emmisions but all i need is the sniffer so i think i'll go carb and press my luck.

tbi would be cool but i don't know much about it, i do have headers and y-pipe already and was planning a custom set-up from there back

i also didn't think the th400 would be such a bitch, but truthfully i would rather go with the 700r4 anyway, now i guess i can try to sell the th400 i got for some of the buildup money

the only other question i had was about the interior gauges and such, i really don't want to rip up the interior that much, i want it to look as stock as possible, am i going to bee able to use the stock gauges with the older motor and carb??

 

All the guages on the car will work with a new motor. There is a green wire that goes to a sensor in the intake or cylinder head. This wire is for the temp gauge. There is another bigger sensor on the back of the intake with one wire going to it. That is the oil pressure gauge.