Im thinking about building a 400 SBC for my Bird', and would like to know your experiences with building one for a Third Gen. I want to run an automatic with a stall speed of around 2800, you think a TH350 will work for me? I already have a 10 bolt with 3.73 gears so I dont think Ill have to do anything with the rear, unless you guys suggest something.

I know there have been threads in the past, but I wasnt able to find exactly what I was looking for. Thanks in advance guys!

 

It's a small block Chevy. It's externally balanced. Stock factory 400 heads are absolute junk. The heads have to have steam holes drilled using a 400 head gasket as a template. Many people have put TH350's in 3rd gens. 10 bolts need beefing up to handle more torque/HP.

What exactly couldn't you find that you were looking for?

 

Honestly depends on your power goal. There are a lot of rumors about the 400 engine, whether it's the two bolts are stronger than the four bolts, or they consistently blow head gaskets, etc. I'm building a boosted version of the 400 myself. As far as suggestions though, well, you can never go wrong with more cubic inches, it's free horsepower, and loads more torque potential. If you plan on running it daily for the street, I would scrap the TH350 idea, not that it's a bad tranny (it's not), but w/gas prices and the additional cubic inch displacement, you'll want that overdrive. I would also recommend higher gears (lower numerically) out back; 3.27's (or 3.55's tops). Good luck....

 

Have one for sale if interested. Here is the link.
https://www.thirdgen.org/forums/engi...light=sale+406

 

400s are great for power only draw backs are steam holes and head gaskets IMO. Im using a th400 in mine. More strength and more fun to drive on streets and at the track but youll wanna stay off the highway with no overdrive. So if you plan on highway driving id get a performance built 700r4. also if you plan on putting 400 + hp at the motor id beef up the rear end without hesitation. I run a 9 inch, but as long as you are NA a 12 will do or even a beefed up 10 if you do it right. Also if you run the 400 you will neeed to beef up the cooling system a bit to be on the safe side especially if you plan on sitting in traffic.

 

I plan on getting about 400 HP to the wheels, so Im shooting for 450 HP from the motor. About how much will a built 700R4 run? So you would switch out the gears I have (3.73s) to 3.27s or 3.55s?

I dont have $3k cash, and you are a little far from me. What info can you tell me about the motor, have you had it dynoed?

Yeah I plan on running NA, so what all will need to be beefed up in my 10 Bolt? I plan on running the biggest core radiator I can get my hands on, just to be on the safe side for cooling. Also, I plan on running electric cooling fans.

 

I personally don't like going too low (high numerically) of a gear with an automatic transmission, as this is what stall speed is for. 400-RWHP will get you into the ten second zone, provided the tune and suspension is up to par. I'd personally go w/3.27's, 3000'ish stall speed, with a good set of heads, and custom cam tailored for the setup. It's all about the symmetry of the parts being used...

If you can get it done in time, come join us for the GTO vs 3rd Gen event....

 

Understandable, my dad was thinking about a 2800 stall speed. You think that should be fine for my setup and still be streetable? When is this event lol? I plan on parking her for the winter and making this a beginning of fall through the end of winter project and hopefully get it done in time for spring.
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I plan on running in the 11s, so as far as SFCs go what else should I be looking to add to strengthen the car up, anything?

 

I'm thinking I might go with a 400 also. I just came across a pair, and I've wanted to build a long rod 400 for years. The price of the build is about the same for 5.7 rods v/s stock 400 (5.56 I think) but the longer rod produces more torque. This is part of the reason the 383 build is so popular. and remember torque is king, horse power is little more than bragging rights........

 

A pair as in you have an extra block? Im still looking for one lol

 

i had a trans built from Goodfella's in Fla
i got a steroid injected 700 for about $1400 running a 3200 stall

 

I have access to two 400 blocks. A two and a four bolt. If I go that direction I will choose on the one with the best walls. I'd like to not haft to bore and buy new pistons. Neither block is actually for sale, but when you are family..............

 

Yeah yeah, your lucky. My dad still wishing he had his built 400 SBC, cuz now Im stuck scouring around for a 400 I can rebuild lol.