I know there is a 400sb is there such thing as a 400bb? What came in the '76-'79 6.6 liters? Were they a chevy engine?

 

Yes. The 70-72 "400 4-barrel" was actually a 402 big block, which is a .030" over 396. It has essentially the same bore and stroke as the 400 small block which is actualy 401.6.

The "T/A 6.6" was an Olds 403. Not the same thing at all.

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"So many Mustangs, so little time..."
ICON Motorsports

 

Cheverolet did have a 400 BB. RB is right, it was actually the 402. They called it a 400 when they first started production of the 402's for some reason unknown to me. I have never seen it refered to as a 400 in many years but I can remember somewhere reading about it. The 402 has a .01" longer stroke, thats the only difference in the bore x stroke. It's a great engine, I've had mine in the RS for about a year now and love it. As far as having it in in the '76-'79 years, nope. That was pontiac.

 

The "6.6" was an Olds motor. They called the Pontiac 400 a "400". The shakers were badged accordingly, either "T/A 6.6" or "T/A 400".

87: Look around at Impalas and Caprices from 70-72; watch for 400 badges (red "400" on the fender); look under them to see if they're single or dual exhaust. Single = 2-barrel = 4-bolt 400 SB; dual = 4-barrel = 402. I've built quite a few of both over the years, including a couple to go back into the cars as described above. If you ever need another big block, that's the one to get.

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"So many Mustangs, so little time..."
ICON Motorsports

 

Pontiac TA stuff:
The 75 and 76 had the displacement on the shaker, so it would say 400 or 455. The 77 and 78 if it was a 400 HO said T/A 6.6, the other 400's and the 403 just said 6.6 LITRE. The 79 only had one 400, all of them had T/A 6.6, and the 403's had 6.6 LITRE.

The other stuff is as RB said.

 

I own one! Sitting fat between the fenders of my 71 Impala convt. Real torque monster. It's fun killing rice and pickup truck owners running obnoxious straight dual pipes with my rusty old Impala!

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Rob P
89RSconvtZZ4TPI
Edelbrock Hi-Flow Intake
SLP Dual Cold Air Intake
1 5/8" Headers
Semi-Siamesed Runners
MSD6AL/relocated MAT/ AdjFPR/IROC frnt@rear swaybar/wonderbar/steeringbox/alum drvshaft/ Alston SFC/3:23posi disc rear/MAC LCA/H.Adams Panhard Rod/KYB struts/ shocks/
92Z28convt5spd
71Impala convt 402BB
BETTER DRIVING THRU SUPERIOR HORSEPOWER!

 

as already said there was no 400 big block chevy. your question of what was in the 76 to 79 6.6 liters. it is a good thing to point out that no company even gm made a car called a 6.6 liter. that is an engine size not a car name. it is correct that the 400 pontiac stated 6.6 T/A on the shaker and the 403 olds stated 6.6 Litre. remember guys, engine size is not the name of a car.

 

Yes there is such a thing as "400" big block Chevy. I don't know how many more times I'm going to have to say this before it sinks in.

In 70-72 they made "400" cars, mostly Caprices and such. They were either 2-barrel or 4-barrel. A 400 2-barrel was a 4-bolt-main 400 small block, a 400 4-barrel was a 402 big block. The small block and big block are within about one cubic inch of the same size, at 402.

I've never actually had one of the "400 4-barrel" cars, but I've built a few 402s. I recall the badges well. This is not some kind of magazine fodder for some of us, you see: we were there at the time!

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"So many Mustangs, so little time..."
ICON Motorsports

 

I have a 400 BB chevy at the machine shop. They exist. They suck compared to a 400 SBC, IMHO.

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2 1984 Trans Ams
and some other stuff

 

I couldn't let this one slip by.

I've built, raced, raced against, and blowed up 400 smallblocks and 400 bigblocks (396s, 402s, 408s, etc) in my 30 years of hot rodding.

Anything can be built to perform--with enough money.

I like 400 sbs. I LOVE bbs. The early 70s 400 (402) (car engines-trucks were/are a different head) bbs usually had the good open chamber/oval port heads.

You have a much bigger valve size on the bb and plenty of more room to go. Factory head choices are much better (open/closed chambers, oval port/rectangular port, cast iron/aluminum) on the big block. Head design is MUCH better on the bb. The block is much stronger. Steel cranks are easy to find (not to mention a 1/4" stroker from the factory). Good rods, even in mild factory engines.

THE major drawback on the bb is the weight difference (150-175 pounds). Aluminum heads help shave about 45-50 pounds. Lightweight starters-another 10-12 pounds. Aluminum Water pumps-8-10 pounds. And if you have deep pockets, aluminum blocks knock off another 80-100 pounds.

Big blocks got most of their bad rap in the mid 60s when guys thought they should rev like 327s. Stock valves and springs (at that time and in the basic bbs) in the bbs couldn't take 7,500 rpm.

Don't get me wrong, I like 400 small blocks, but, set a 400 sb beside a 400 (402) bb side by side, then hand me $4,000 and I'll build you a stronger bb than you could with the small block.

Been there-done that-several times.
jms

 

Thats what I have now. This is my 2nd one. The first was a 68 corvette 396, had all of the goodies factory 10:1 pistons, Z28 manifold, oval port closed chamber heads ported to match the rect. port manifold. How it ran on the street with a 312/322 sig-erson cam I'll never know. The previous owner had done extensive work on it as the engine for his dragster and then decided to go with a 454. After having a motor like that I swore off SBC's.

 

The 402BB in my Impala is original and it has the 400 emblems on the lower rear fender.
There was a good article in Super Chevy or Chevy HP about how people have snatched up all the 396/427/454 engines but left the 402's alone. Even though its a "small" big block, there is a lot of potential to be found during a rebuild. I can't imagine trying to get my Impala convertible moving with anything but the torque of the big block. That car is HEAVY!

------------------
Rob P
89RSconvtZZ4TPI
Edelbrock Hi-Flow Intake
SLP Dual Cold Air Intake
1 5/8" Headers
Semi-Siamesed Runners
MSD6AL/relocated MAT/ AdjFPR/IROC frnt@rear swaybar/wonderbar/steeringbox/alum drvshaft/ Alston SFC/3:23posi disc rear/MAC LCA/H.Adams Panhard Rod/KYB struts/ shocks/
92Z28convt5spd
71Impala convt 402BB
BETTER DRIVING THRU SUPERIOR HORSEPOWER!

 

Rob, you sure got that "heavy" part right... my other car (well, one of them) is a 74 Caprice convertible with a 454, it went across the scales on the highway once at 5270 lbs. Those sleds need all the motor they can get!

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"So many Mustangs, so little time..."
ICON Motorsports

 

Rob, RB, You guys seem to know these engines real well. I have a question. How far over can I bore my 402? With the factory going .030 is it still possible to go .060 for a bore of 4.185? It's a '71 block and heads if that helps.

 

I don't believe you'll reliably be able to bore a 402 to 4.185". They usually will only safely go .030" more. You might want to get the walls sonically checked though, some will go that far, it's just not anywhere near 100% of them.

------------------
"So many Mustangs, so little time..."
ICON Motorsports

 

RB, Next time lie to me. That's not what I wanted to hear. I have a feeling I broke a ring so out comes the 402. I hope I can get by with .040".

 

OH NO!!!! I hate it when I hear stuff like that. Probably not as much as you though.

Take it to a good shop and get them to check the walls with a sonic tester. You might get lucky if the block doesn't have too much core shift.

But think of it this way: if your block is in fact hosed, that just gives you a good excuse to find a 454 block, and turn your motor into a 427.

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"So many Mustangs, so little time..."
ICON Motorsports

 

Punch that thing out. I've gone .060 many times. Check the core shift at the front cam bearing and if the hole is centered it will easily go .060 over.

If you are worried, have it sonic tested. To get an idea how thick a bb is, look at the outside of the cylinder wall (#s 7 and 8) in the water passages between the back cylinder on each side and the end of the deck.

I have reliably heard (but didn't do this myself) that certain 402 "K" blocks would go out to 4.250 and live on the street.

I do know that the early 396s (4 bolt main blocks) would EASILY go 4.250 plus .060! When the 427 came out in '66, many 396s were punched out to that size. Those blocks are monster thick.

I also know guys around here with pull-trucks that punch 454s .185 over but they also half fill the water passages.

Big Blocks are fun!
jms

 

Holy Crap, RB! I knew the converts were a little heavier, but I didn't know they had almost 600 lbs on the sedans.

You pro'lly scare the crap out of even those Ford Extinction drivers - just as much mass, but lower, wider, and faster! (And better looking, too!)

Here dino, dino, dino....

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Later,
Vader
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"I'm'a do Things My Way - It's My way or the Highway."
Adobe Acrobat Reader

 

I've been known to "throw my weight around" in traffic before. Scares the hell out of the Geo drivers!

------------------
Rob P
89RSconvtZZ4TPI
Edelbrock Hi-Flow Intake
SLP Dual Cold Air Intake
1 5/8" Headers
Semi-Siamesed Runners
MSD6AL/relocated MAT/ AdjFPR/IROC frnt@rear swaybar/wonderbar/steeringbox/alum drvshaft/ Alston SFC/3:23posi disc rear/MAC LCA/H.Adams Panhard Rod/KYB struts/ shocks/
92Z28convt5spd
71Impala convt 402BB
BETTER DRIVING THRU SUPERIOR HORSEPOWER!

 

no such thing once again as a 400 big block chevy. 402 cubic inches does not make for 400. the 402 cubic inch cars were listed as 400 in some and 396 in others, but they were still a 402. how they are listed and what they really are, two different things. calculate it out and you'll get 402 cubic inches, not 400. 400 is small block, 402 is big block for chevy.

 

Some of the older Chevy trucks came out with 400 badges on them, but they were actually 396's bored .030 over to 402. That has some people mixed up on a 400 being a BB.

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350 4 bolt main, Speed-O-Motive 383 stroker kit, re-sized rods ground for clearance,TRW Forged pistons,10.7:1 compression,HPC Coated RPM intake, Speed Demon 750 cfm carb,World Products Sportsman II heads,2.02/1.60 valves, Comp Cam 1.6 roller rockers, Comp Xtreme 284 cam,240/246@.050 with .540 lift,Crane pushrods,ATI damper,Proform HEI and MSD6A box,HPC coated 1 5/8 headers, 2.5" exhaust with 40 series mufflers,TH350 with B&M 3000 stall, Powertrax NoSlip Locker, 4.11 gears.

 

Ummm...

[This message has been edited by JAYDUBB (edited March 23, 2001).]

 

The 400 BBC is nothing more than a .030 over 396 that Chevrolet built from 1970-1972. Its a 396 bored .030 over from the factory. To keep the confusion down (Huh? It caused more confusion than it tried to avoid!), they called it a 400, when its actually a 402! So enough! Stop bickering!


Can the Moderators close this thread? Its getting on my nerves!




[This message has been edited by JAYDUBB (edited March 23, 2001).]