Anyone running a Small Block 400?

[Hazieview]

I have a small block 400 (bored 30 over) with an RV cam in it backed by a beefed up 350 turbo trani and I believe like .308 gears (whatever was stock in '87)

It'll get down that's for sure. I wish I had a little more power out of it but it'll scare ya if you let it haha!

Tell me about your SB400 setup and how you like it!

Later!

[b454rat]

Sounds like a mild but strong 400. I had many of them, and loved them all. I have 2 now, one in a 79 4wd dually I just picked up, and one that is going in my 92 Blazer. I built a 406 for my old 90 GMC years ago. That was an awesome motor. The dually is all stock, 80k-ish miles, has more get up and go than my S-10 Blazer does, and I thought that did OK....

[Thumpin455]

I have a 400 shortblock that was going in my Blazer, until a tree fell and crushed the Blazer. Its getting Vortec heads and a mild 224@.050 cam, and a dual plane intake. Not sure what its going in yet, maybe the S10 blazer since it didnt get hit by the tree.

[72BlckButy]

My project has a 400SB in it. As far as I know, it was installed by a previous owner, and it has a mild rv cam in it, edelbrock intake, rochester carb, and dynomax ceramic full length headers. We haven't been able to tear into it yet, so I don't know what all has been done to it. I've heard they are strong running motors, and so far so good. It's backed by a TB350 with a mild shift kid.

[Hoods69BadBowTie]

I have heard nothing but good stuff about them. I am hoping to get my hands on one sometime in the future.

[fossilrunner]

Ive got a stock 400 in my '78 jimmy. runs awesome. Great torque to. Im probably only gonna do bolt ons though since my nova sets all my money

[Hazieview]

Originally Posted by b454rat

Sounds like a mild but strong 400.

Your right about that. I couldn't agree more. Mild at best but really tough! haha!

I thought about swapping mine for a 350 but I just can't. When it comes down to it I just love the torque. I mean I really dont want to go 100+ miles per hour on the highway. I like getting to 70 as quick as I can and then I'm content. It's also fun to burn a little rubber along the way.

Has any body ever seen a TBI sb400? I know it can be done but it's really expensive $$$!!!

[tvblazer78]

I have a 400 in my K5,

Its now 406 small block with Dirt II aluminum heads / 292 comp cam / Holly 750 DP / Edelbock Air-Gap intake / Mallory ignition

it takes my blazer down a 1/8 a 8.3 over 80 MPH

[Walts_restoration]

im thinking about building a 377 stroker out of a 400 i have, i still have to check it out and mangaflux it.

By 377, i mean 400 w/ 350 crankshaft.

Should be a fun little high rpm screamer, as the tuners call it "over square" because its got more bore than stroke.

[PhilaTruck]

I have a 406 w/ lightly ported WPII iron heads • 244/250 (at .050) • (282/285 advertised) • .521/.533 lift • 104 LCA (It has a "little" lope.) • 9.25:1 • modified Q-Jet • 700R4 • 2.73:1 (soon to be 3.73)

I'm not ready to take it to the track yet and the speedo doesn't work. (I'm replacing the whole cluster with Swervin's tach cluster.)

It has grunt aplenty, but really gets going at the top-end. Looking forward to getting the RPMs more in the operating range with the rear change, even so it's not bashful about tire-spanking.

I get equal amounts of smiles and glares from people in the neighborhood. It sounds nasty rumbling down the street. Can wait to switch out to the 1 3/4 primary Hedmans dumping into my cheap cherry bombs. This engine is not nearly as loud as most motorcycles in the area, and doesn't sound the same as all of the new Dodge trucks. I like the unusual sound. my quick build list

[Pyrotechnic]

Originally Posted by PhilaTruck

I have a 406 w/ lightly ported WPII iron heads • 244/250 (at .050) • (282/285 advertised) • .521/.533 lift • 104 LCA (It has a "little" lope.) • 9.25:1 • modified Q-Jet • 700R4 • 2.73:1 (soon to be 3.73)I'm not ready to take it to the track yet and the speedo doesn't work. (I'm replacing the whole cluster with Swervin's tach cluster.)

It has grunt aplenty, but really gets going at the top-end. Looking forward to getting the RPMs more in the operating range with the rear change, even so it's not bashful about tire-spanking.

I get equal amounts of smiles and glares from people in the neighborhood. It sounds nasty rumbling down the street. Can wait to switch out to the 1 3/4 primary Hedmans dumping into my cheap cherry bombs. This engine is not nearly as loud as most motorcycles in the area, and doesn't sound the same as all of the new Dodge trucks. I like the unusual sound. my quick build list

I had long tubes with glasspacks bolted straight up to the collectors on my 350 for awhile. I put in a mild RV cam and it did help but it still didn't really start pulling till about 3000 RPM.

I took off the glasspacks and had a full exhaust system install. 2.5 true duals all the way to the rear bumper with 50 series flowmasters and a cross over pipe. Now it starts pulling hard at about 1500-2000 and 3000+ is just as good as it used to be. Not to mention the exhaust note is great. I went with the quieter 50's because it's my daily driver and I do a lot of long highway trips. I had it brought out to the rear bumper to cut noise in the cab, and for looks too.

A real exhaust would widen your powerband towards the low end a little which is especially better for overdrive, where that extra torque will keep the motor from downshifting to third on hills.

[abebummy26]

My dad told me every body hated these things back in the day coud not keep them going at all.

[b454rat]

I built a TBI 406 for my old truck years ago. The fuel system was 100%stock. Only had new parts.

.030" over 400 4 bolt
KB pistons IIRC 23cc dish
5.7" rods, ARP bolts
stock crank, turned and polished
new stock style balancer and SFI flexplate
rotating assembly balanced
Comp Cams Xtrme Energy 268 cam/lifters
Flowtech headers/y-pipe
3" single in Flow, dual 2 1/2" out
stock TBI heads, just rebuilt
comp ratio was 9.8 I think.

Ran on pump gas, 87 octane at that.

Had a sweet lopey idle, sounded awesome.

Everyone says that you need to do computer mods for it to work, well I didn't and it run just fine. It would probly run better with a tune, but sold the truck not long after I put the motor in.

I plan on building another TBI 406. This time gonna use a set of Vortecs that I have, along with a TBI from a 454. Guessing it should make about 425 and 450 ft/lb of torque. Probly going in the 4wd dually I just got. As it is now, the truck doesn't have a problem in the power department..

[PhilaTruck]

Originally Posted by Pyrotechnic

I had long tubes with glasspacks bolted straight up to the collectors on my 350 for awhile. I put in a mild RV cam and it did help but it still didn't really start pulling till about 3000 RPM.

I took off the glasspacks and had a full exhaust system install. 2.5 true duals all the way to the rear bumper with 50 series flowmasters and a cross over pipe. Now it starts pulling hard at about 1500-2000 and 3000+ is just as good as it used to be. Not to mention the exhaust note is great. I went with the quieter 50's because it's my daily driver and I do a lot of long highway trips. I had it brought out to the rear bumper to cut noise in the cab, and for looks too.

A real exhaust would widen your powerband towards the low end a little which is especially better for overdrive, where that extra torque will keep the motor from downshifting to third on hills.

I know, I know. I just don't feel like spending the money right now. I was looking at an X pipe system from a board vendor (can't remember who, right now) but I know the benefits are significant. That's great advice, thanks, Pyro. I don't really care about the sound, my mufflers were cheap, cheap, cheap and I wanted something to slap on 'til I did it right. I think I'll put those pypes on my list for this summer.

I wanted a TBI set-up until I saw everyone was doing it. (It's a great idea, I just wanted to do my own thing.) Thought hard about an IR system, too much $$$ and not enough local expertise to set up Webers or Dellortos. So I decided to do something radical and stay with my Q-Jet (Thanks, Doug Roe)

TBI with a pair of Vortecs should really pull. That will be a great motor. Here's a great 406 build on Carcraft.com

[Hazieview]

Originally Posted by Pyrotechnic

A real exhaust would widen your powerband towards the low end a little which is especially better for overdrive, where that extra torque will keep the motor from downshifting to third on hills.

This reminded me of something....

I have a 3 speed 350turbo trani (no overdrive).

When I drive down the highway I dont see any reason to down shift manually (my cable is not hooked up).... If I did I would only stay in second for like two seconds before i had to shift back.

Do you all see any reason to hook up my downshift cable? I dont think I need it do you?