Hey guys,

In my area I've found someone selling a 1980 Pontiac Firebird with a 400 (rebuilt) and a 4-speed. This person doesn't really know much about the car at all, and is selling it dirt cheap. I'm pretty much only interested in the motor and tranny now, but who knows, maybe I'll like the 'bird. But anyway, I know the 400 is not the original motor/tranny for this car. I've heard before that there were differences between pontiac and chevy small blocks. I'm thinking that this must be a chevy 400 since I don't know as pontiac ever offered a 400 ci engine. Is this true? And if it is a pontiac block, what would the difference be?

Thanks for the help.

 

Pontiac did have a 400 from 1967 to about 1979. Then they had an OLDS 403. The Pontiac heads look different than small block chevy, the exhaust ports come out a couple of inches from the head, & the headers kind of bolt on from the bottom not the side.

 

Pontiac never had a small block or big block. They are all based on one block, whether it's a 455, 287, or the 400. The Pontiac 400 is known for its low end torque. It's a good engine. Other ways to tell if it is a Pontiac - the distributor rotates counter-clockwise, and there is a valley pan underneath the intake manifold.

 

Hopefully this motor will turn out to be a Chevy and not a Pontiac. For the price it doesn't sound like it can be beat. I wouldn't be putting it in the 'vette anyway, since I just built a 450 HP 383 for the 'vette. I just thought that it may be nice to have around for a future build. And that 4-speed might go well behind the 383 in the Corvette.


*edit* just got an email back from the woman with the car, and she says she's pretty sure it's a Chevy 400. This may be a victory.

 

I'd rather have the Pontiac 400. Make it into a stroker and you have a 461. Keep that in mind if it does turn out to be a Pontiac engine!

 

? Rebuilt chevy 400sbc ?
Already rebuilt? Common sbc400 rebuilds are bored +20 over & +30 over. As often as not, Sbc400 do not have room for "successful" +60 over re-bore. This one may or may not have room for another re-bore and there's No way to know without disassembly and close measurement. There are relatively few desirable sbc400 piston choices is sizes other than std, +30, +40. Weigh your options before you shoot.

 

I do know that the car has not been driven since the engine has been rebuilt, so it should still be pretty fresh. The situation is that this woman has had the Firebird for 12 years, and every now and then her now ex husband would get interested in it. He rebuilt the motor, and since then has only really fired it up a few times, and lost interest in the car. Now they're divorced, and she wants to get rid of it. Seeing as how this guy never had much interest in the car, I'm guessing he probably just did a stock rebuild with new bearings, rings, etc. Even if it's been bored once, since it hasn't been run much since then it would probably only need to be honed.

 

Depends on the core. I have a +60 400 block in my basement waiting for a rebuild.

 

Pontiac 400's were a big boat anchor. Kind of like a big block chevy in block dimesions & weight, but entirely different in bore stroke and parts.

Gas sucking pig smog motors. 70's 400 Firebirds were not hot rods. Well maybe if you compare them to the C-3 Vettes in the same time frame.

 

Yes true, they were big heavy boat anchors.....BUT to be completely honest with you, they make WAY better street motors then SBCs... The midrange torque/hp out of those things were phenominal, ESPECIALLY considering the pontiac heads are HORRIBLE. The pros of the pontiac is that its a big thick block, already has a good bore/stroke relationship for a street motor, no need for stroking/clearancing(although now their are stroker kits out for them which is even better). They make great power, even with low compression...True the peak HP might not top that of an evenly equipped 406/415" sbc but the low to mid range will kill it on the street and strip. I built MANY of those 400/455 motors for street cars they were all a blast and did not require all this high dollar hardware to make power. The last 455 I built with a hyd flat tappet, Edelbrock street heads and a torquer II intake ran 11.30s in a Tempest wagon. A buddy of mine is running a 10.5-1 455 in a 68 Firebird, its got a mild Ultradyne solid flat tappet and Edelbrock RPM intake and runs 11.50s@116. These are like $3-4k engines.....In the SBC world, we gotta spend $6-7k to get that performance...

Its the torque and tall gearing that makes em run so well...Very streetable... the only weak point on a Pontiac is the stock cast rods..

I would MUCH rather have a Pontiac powerplant then a SBC for strong running street motors that actually get driven and don't have to scream to 7k to run high 11s...LOL

Unfortunately, it would be sacriligous to put one in a vette so....

 

The water pump looks way diffrent to.

 

This is a pontiac 400.

 

OH also, on the late 70s Firebirds, I had one of the base 400s with 7.7-1 compression(yes for real), the car ran 14.70s with a TH350 and 2.56 gears, completely stock. We put a torque II intake/spacer on it with a 750dp, headers, 3" exhaust and a Sig Erson(yes...I know) hyd flat cam in. Stuck a el cheapo 2500 stall converter in it with a 3.73 gear swap and the car ran 13.40s@102... That was with over 100k on the motor..that car weighed 3750lbs with me in it. If I did all that same stuff to my base 71 vette, I would be doing good to break 14.20s, let alone a late 70s C3 tank.

 

Never underestimate a Pontiac. I built them in the 80's and many BB Chevy guys lost a lot of money.

 

Pontiacs are a lot of fun to build. Many a BB Chevy driver was dollars down after racing one.

 

I agree..... We hustled many BBC owners back in the mid 90s running our pontiacs.. They didn't know what they were looking at... all they saw was steel heads with d-port styled headers and a low rise edelbrock torquer II and didn't think they were $hit....I can't tell you how many Dart headed 383 Novas and Camaros we put on the trailer back then..

Hell my daily driver in 95-96 was a 78 TA with a 406" pontiac that would 60' 1.58s with 3.42 gears and would run 11.80-12.0s back then....that was about a $2500 motor in a 3600lb car that I drove everywhere on pump gas. Man I miss those old days...I wish I could build a SBC to run mid 11s for $3k and be driveable. You know now days, the technology has come so far in the Pontiac world, there is no telling how strong you could make one...I bet 550hp/600tq would be a cinch in a 455 now...back then Edelbrock had JUST come out with the aluminum heads that were $2k....and even they didn't flow that well, don't even get me started on the stroker kits that make 490".

 

I'm building a 455 for my '78 Firebird, shooting for a streetable 525 hp, KRE aluminum heads, mated to a TKO 5-speed. Should be a fun ride.

 

Can you say "SUPER SD"?
I read about some new heads for the Pontiac a few months ago, can't remember the builder, that were suppose to put the EdleBrock's to shame.
Ever read Jim Hand's stuff?

 

Those are the KRE heads (Kaufmann Racing Equipment), the ones that I'm using. I have Jim's book on building a Pontiac mill. Good stuff, and he backs it up with his ten second wagon.

 

..... in the early-'90s, I bracket-raced against a guy who ran a 400-Poncho in a '79 Firebird that turned 12.00s with 4.56 gears:
he shelled the 10-bolt ring & pinion one Friday evening, so Saturday morning, he slapped-in a set of 3.42s he had laying-around, and Sunday he ran 12-teens.