WHAT DO YOU GUYS THINK ON PONTIAC 400 ENGINE AND A CHEVY 350 WHICH ENGINE CAN I GET MORE HP AND TORQUE. NEED HELP ON DECIDING WHICH ENGINE TO PUT ON MY CAR.

 

How much work do you want to do? How much money do you want to spend? Almost the entire aftermarket is geared to the SBC, parts are cheap and a 350 will bolt right in the place of your 305, while the Pontiac engine will require fabrication to fit. You can make up the cubic inch advantage of the Pontiac engine as well, leaving no advantage to the 400 over the 350 as far as power. Unless you just want to do something less common, go with the SBC.

 

WELL, I GOT AROUND $ 2,000.00 TO SPEND. THE 400 I READY HAVE IT
WITH TRANS.

 

Not enough information, really. Which 350? Which 400? Stock, or modified?

There are trick heads available for the Pontiacs, too. (Kauffman Racing sells some great Aluminum heads now) and you can easily bore and stroke a 400 Pontiac out to about 460CID, but they are not cheap to build compared to a SBC or SBF(ak! Sorry)

Power per dollar and less hassle, go with a 350 Chevy. Most potential and a total sleeper because Chevy guys will never know it's a 460, go with the Pontiac, but it will be a lot more expensive and more hassle to build and adapt to your car in the long run.

Stock for stock, it would depend on what heads and cam are in the engine. An early LT-1 Vs a 400 Poncho out of a GTO will be about a toss up, but I doubt that is what you have...

Troy
So Cal

 

THE ENGINE IS FROM A 78 TA WELL, THATS WHAT THE GUY WHO SOLD IT SAID. AS FAR AS THEY ENGINE IS COMPLETELY STOCK.

 

good news for the pontiac 400, I was talking to a guy at work and he said his buddy that owns a junkyard said the only thing that slows down or stops the crusher is the crankshaft of a pontiac 400. says something for strenght.

 

Not to rag on chevy at all, but I kinda wished that pontiac still made engines. Considering I own a Firebird it would be cool to have a pontiac engine in there instead of a SBC. Chevy is great too, but you firebird owners see my point.

 

Make sure it's really a Pontiac engine. A lot of '78 Trans Ams came with an Olds 403, and they are boat anchors in comparison.

Pontiac changed compression ratios on all their motors by changing cylinder head chamber size, all the lower ends are pretty much interchanable. You can scout out some earlier heads and increase compression pretty easily, cam it, put on some headers, and then have to struggle with how to get it into your car. I think a place in Mass or something has a kit to do it, the place is called Indian Adventures. The Pontiac engines are really very good units when tuned correctly, but swapping it in might be a can of worms.

I would probably spend my $2,000 on a base GM 350 Crate motor, and throw a better cam in it down the road. Something to consider for the sake of ease and getting rolling as quickly as possible.

Plus, you can probably sell the 400 and trans to someone on one of the Pontiac sites...

Good Luck

Troy
So Cal

 

If the engine was from a T/A, ws it manual or auto? Cali cars got the 403 auto, rest of the world got the good 400 w/either TH-350 of the T-10. cr should be around 8.5:1, 185hp & 325~330 tq. Heads, if the 400 (which will be cast on block, forget if on both sides by freeze plugs) should be the 6X-4 for the higher compression. A simple cam change will make uber more power. And there is a nice aftermarket for the Tin Indian big bore motor. There are even shorty headers now, may fit the third gen bay, Sciencam, the kind Jim Taylor is now using, . Hell, shizz loads of goodies out there, just gotta know where to look
:rockon:

for about $800~1k, you can get the crank & rods for a 4.25 stroke crank w/3" mains

edit: Click for the good stuff

 

Pontiac 400's will put out more HP, but they are also more expensive to build. I've got about $6000 into my Poncho 455, and it's not even in the car yet, but we're looking at around 850 HP 700 ft lbs when it's done. Parts are readily available for SBC, just the swap headers I've got were over $500, so you have to look at the total cost, not just engine costs. The cylinder heads should be 6X heads on that engine, which are pretty good for pump gas, and you should be able to get 450 horses easy with the right cam/intake combo even with 6X heads. I'm running 7K3 heads on a 455, which puts my compression about 11:1, which is waaaay too much for a street engine, with the 6X's, you'll be at about 8.5 to 1, perfect for unleaded fuel.

 

and your'running a TH-350 w/that engine???

 

Yeah, I've got a few of them, and It has all the hardened goodies, and a lot less driveline loss. Converter is a 3600 stall PI multi disk unit, and a metal matrix driveshaft. Wonder how long the 9 bolt is gonna hold up?

 

any chance of a TH200r-4, gives you overdrive and will bolt right up to any B-O-P block . That's a hint for others wanting to swap in real Poncho Power!!!

 

?????

How so? Is the brand name really that important, or are we really talking about how to go fast on little $$$$$?

Pontiac 400s will not put out any more (or less) torque than any other brand of 400 CID engine, within a couple of per cent. That's got to be one of the most laughable ideas on the whole automotive Internet: that some finite non-zero number of gasoline molecules (CID) get themselves into some cast-iron or part iron and part aluminum volume, and look around themselves while sampling the cast-iron owner's fondness for that particular brand of casting, and decide how much energy they're going to release. How ridiculous. A Pontiac 400, or a Chevy 396, or a crappy F*rd 400 or even a Mopar 400 lean-burn, will all produce essentially the identical same peak torque at whatever their peak torque RPM is given the same induction system characterisitics, which is a function of cylinder fill. Nothing else.

Rich's comments are a good example of what's right and what's wrong with builders of unusual motors. He freely admits that he has a jaw-dropping amount of money in his motor (truth); but at the same time, humorously overestimates its HP output (by I'd guess at least 20%, probably by more than 25%). And that's just the motor: he hasn't installed it in his car yet, nor driven it back and forth to and from work a few times without something falling off or breaking. On the other hand, my 400 Chevy drove over 100,000 miles in my 83 car, including a couple of more or less coast-to-coast road trips, with good gas mileage, the stock T-5, and no malfunctions on the road. I doubt the typical Pontiac (or Buick or Olds) partisans on this board that will tell you all about how great their favorite cast-iron brand is, can claim anywhere near that good of a reliability record. Not that any of those brands is "bad", or "better" than others; we're talking suitability for purpose here, remember, not "good" or "bad".

There's alot more costs and payoffs involved in a motor swao than the "cost" of the motor itself, or your beat-off about how much HP you hallucinate it's going to produce. But, as someone who owned 78 model cars when they were new, I can tell you that a 78 Trans Am 400 was slower than a Chevy Z28 350 in the same year..... and the Chevy 350s that I had back then ( a 78 Z28 and a 79 Z28) were "rated" at 180 HP. The Pontiacs were slower than that. I drive a 83 L69 car now, which came from the factory "rated" at 190 HP, and would drill the 2nd gen cars I owned at the same time so bad it was hardly even funny. Go figure.

Want to to get beat by 305s? Put that 78 Pontiac 400 in your car, and enjoy pulling up next to me at a traffic light and watching my tail lights grow smaller in the distance.

 

in other words, the Chief Many Horses is the way to go.

 

Man just build the 350. The Pontiac 400s were a pretty stout motor but they have problems. Plus parts are more costly than a 350. Its up to you though.

 

You know absolutely nothing about my combo, since I've posted nothing about it. You think I've overestimated my HP? That's pretty funny since my engine is an EXACT duplicate of another engine that has already been on the dyno and put out just over 780 RWHP behind a TH400. Enough said on that. The fact as you put it is that I will NEVER drive this car to back and forth to work, because I abide by the laws, and a 467 ci Pontiac engine in an '85 Trans Am will never be street legal, this is a track engine only.

I couldn't tell you about reliability, since all the Pontiac engines I've built were made for max horsepower, and not reliability, you can't build a 450 HP engine, and expect it to last 200,000 miles trouble free. My daily drivers are a different story. I've got 215,000 miles on my 1995 Mercury Cougar 4.6, and have never had the valve covers off of it. I also had 375,000 miles on a 1986 Monte Carlo that the only thing I did was put valve seals in it.

I can tell you that I'm not biased towards Pontiac engines, chevy engines, or any other engines. Right now in my stable, I have a Ford 302 EFI engine going, and Ford 347 stroker, a Ford 351 Cleveland 4V, my Pontiac 467, 4 Pontiac 400's, 2 Chevy 350's, and a newly aquired 383 kit for my 1972 Chevy Vega. All of these are built for drag racing, so I don't expect longevity, just horsepower.

 

I dont think engine builders should duplicate another engine builders work. If you know how to work the math, measurements, and flow chart, you dont need to copycat.
450hp all motor is hard to come by and be legal. But it can be done. Pro Chargers, super chargers and turbos make it possible and MORE efficiant(with EFI).

 

I dont know guys, I've had a lot of experience with BOP motors, Ive owned two olds cutlass's and a 72 bird. IMO the pontiac motor is going to make a little more grunt than the chevy motor. It always seems that way, maye a little more torque. On the downside though the parts cost about 3 times as much. And whoever said a 403 old engine is a boat anchor needs to stick with chevys. I've seen 403 powered birds walk ALL OVER 350 and 400 powered camaros. Olds has always made a good engine. Personally, if it wasnt for the money, thats what I would be driving.

 

My engine was actually built by myself and the guy who originated the combo, since it's a known good combo. He's since moved on to a tunnel rammed 500+ cubic inch engine. Everyone on this board copies other people's combos, you know it works, so why not????

 

I wasnt trying to say mimicing motor combos is wrong. I mean if its a hobby and not a profession and your going to spend the money then I'd be on the safe side and try to get what I paid for. But as a profession I think its not as exciting. I think it should be a proccess of creating your own style, not someone elses (opinion).

 

I know first hand of how reliable Pontiac 400's are. We have a 76 Formula 400 w/ 4spd outside. My bro drove it for 4 years never had a problem. The motor has somewhere 190k miles plus on it. It sat for 4 years, we went outside and the damn thing cranked on the first try. The 400's are tq. monsters stock, but do not act like a 400 is not reliable, you're wrong there. I've also seen 350's with 200k miles plus, both the 400 and the 350 are very reliable motors.

Also no way in hell a stock 305 (TBI) will beat a stock 400. My 90 Formy 305 has no where near the power of a 76 400.

 

Amen to that LedZep, Chevys are great, but that doesnt mean that a pontiac 400 is gonna get beat by a stock 305. Just aint gonna happen.

 

Well, this thread is getting into a nice little flame war. The original question was too open-ended, we don't really know what engine it is (there's a "according to the seller" statement, which is often worth something less than a hill of beans), a lot of this "information" has got to be totally worthless to the originator for a street car, we all know putting a Pontiac engine in a 3rd gen f-body is not cheap or easy, "Pontiac is better than Chevy", "Chevy is better than Pontiac", all the info needed is available with a simple search, yadda yadda yadda, blah blah blah, ad nauseum.

Say good night, Gracie.