Look I know this isn't a chevy site but I'm thinking about selling my truck and buying a 1969 Firebird. See here's my problem. My buddy says it has a 350 Big Block, is it a big block or a small block with taller deck height? I know it is a 350 Rocket motor just well check this out.

Here's the only info I could find...

As for the 350, its a small block. There never has been a 350 big block, whether it was an olds or not, it simply doesnt exist. The small blocks go as follows: 262,265,267,283,302(Z28, yes Chev had a 302 as well)305,307,327,350 and the 400. The big blocks go like this: 348,409 and the 427 with a bore and stroke of 4.312" x 3.65" (These three are the first BBC's) then it goes 366,396,402(the catch with this is, the 396 is the 402, Chev made a mistake on a certain portion of 396's made by giving them a 0.0035 overbore if I am corect by the specs)then we got 427 with the bore and stroke of 4.250" x 3.76 then it goes 454 and 502. Thats it. And just to show, ive got myself a 383 Stroker, 350 SMALL block, with a 400 SMALL BLOCK crank. The 350 bore is 4.00' and the stroke is 3.48, and the bore of a 400 is 4.125 and the stroke is 3.75, now add that stroke to a 4.00" bore. Makes one fast engine! The reverse can be done by taking a 350 crank and a 400 block to make 377.

Now with that said what do you guys think? Is there a 350 Rocket big block??

 

Your 1969 has, or at least originally had, a Pontiac 350. Chevy, Buick, Olds, Pontiac, and Cadillac all made their own engines for a while, think Pontiac dropped theirs in the late 1970s to start using GM standard (Chevy). Olds and Buick dropped theirs around the same time. The Pontiac 350, 400, and 455 were all the same block, and, yes, I have heard them termed "big blocks", but they are not the same as the Chevy big-block engines. Pontiac 350 has a 3.875 bore and 3.75 stroke (actually is 354 CID), their 400 is a 4.125 bore and 3.75 stroke but not interchangeable with Chevy 400. Totally different engines. Olds and Buick had their own 350s and 455s also, again not at all the same engine as the Chevy 454 or Poncho 455. Olds had a 403 also. Olds engines had big bore and short stroke for highway cruising, Buicks and Pontiacs more "square", and Chevy kind of in between. there were smaller engines--Pontiac 265 and 301, Olds 307, etc., and I'm not sure whether they were the same blocks or smaller ones. Am thinking the Poncho 265-301 were "small" blocks, as compared to the 350-400-455. The "Rocket" was Oldsmobile, not Pontiac. Hope this helps. Disclaimer--it's been years since I played with GMs, had two '74 Pontiacs and at one time was pretty familiar with them, but memory turns gray faster than hair, ya know.

And of course, that Firebird is 35 years old now. It may or may not have the original engine, could have been through several by now, and not at all unusual to find Chevy engines in older Firebirds, because parts are much easier to find for Chevies than the old Ponchos.

 

Well my best friends dad built the motor before he sold it the car. He told me it was a rocket 350, so that must mean that it was out of an oldsmobile. Hmm, get's me thinking..so there is a 350 BB then?

 

I don't know how Pontiac engines compared to Chevies, because I owned Pontiacs and friend had Oldsmobiles, but yes, the 350-400-455 Pontiacs were considered big-blocks.

 

sweet mike thanks. They are considered big block but have the same displacement as a chevy small block, that's odd. Do you know what kind of power those 350's made? Probably low 200 hp right? None of those old motors were very good for effecient power.

 

My '74 Lemans (350, swapped from 2-bbl to 4-bbl) was rated IIRC at about 180 HP, maybe 200 after I put the 4-bbl on it. The Pontiacs had long strokes, revved slow but made a gob of torque. Great engines for clearing a stoplight. Never understood why GMC didn't use them in trucks instead of the Chevies. Not to say they were slow--my other '74 was a Grand Am (which was really something then, not just a cheap family sedan) with 455 4-speed, and it could move itself pretty good for a 4500-pound car. Surprised more than a few Mustangs and Camaros and would have done even better if I'd known how to shift it quickly.

 

sweet so that 350 BB is a good start for a drag motor? Cause that'd be all I do. I'm just a cruiser really. I'll race a couple of times maybe but not really on the highway. That's pretty low numbers for a 350 don't you think?

 

If you want a drag motor, go with Chevy. Lot more parts available, and less expensive. You can build a Pontiac motor today but I don't think you would have the selection of parts and cool stuff that are made for the Chevy, Ford, and Mopar engines. The other thing is--if the Firebird has an Olds engine, not a Pontiac, you're even more limited.

The LeMans wasn't a high-performance car, so it had a pretty mild version of the 350. Pontiac put 400s in the Trans-Ams, they were quite a bit more potent, and a few hot 455s in the late 60s and early 70s.

EDIT- No need to use the quote function if it is clear who you are responding to. Please help save bandwidth. -Admin

 

The Rocket 350, is a small block olds motor. It's the same block the 307 was made out of. It is also the same as the GM 5.7 diesel block. It's a good motor, and will last a long time. They don't make alot of torque, but make gobs of horsepower. In 1979 the Chevy 350 was 160hp and 170lbs tq, the Olds 350 was 170hp and 160ftlbs tq. So they each had advantages, but wilthout some serious work a stock 350 will be quicker off the line. To answer the "Is it a big block?" question, if it's a Rocket, then no.

 

There is no such thing as a 350 bb unless you are talking about the 348 w chev engine from the late 50's early 60's. There is no big block and small block with pontiac engines they are all medium blocks same external dementions exetraa. If it is a 350 olds you then it is a small block olds. Olds do have big blocks but they are the 400 425 and 455. btw as previously mention there is also a 403 sb olds. After 73 or so some of the olds 350's received lighter block castings and aren't really suitable for performance use so the pre 73 blocks are a better choice.

 

This is a common missconception there is no big and small block pontiac engines

 

Calgary, looks like you're right. Been a long time since I got into GMs of any sort, and longer since the old Ponchos.

http://www.pontiacpower.com/Bigblock.htm

http://www.popularhotrodding.com/eng...9PHREMPontiac/

The 265 and 301 were a lower-deck version of the same block, so can't really be considered "small blocks" either.

 

oh and just a FYI chevy called the 402 a 396 for insurance purposes. Anything under 400 was cheaper insurance rates, so they just called the 402 a 396 for cheaper rates, even though it was actually a 402. And one very quick motor and car.

 

ya the 301 was kind of the black sheep in the pontiac family (one that would like to be forgotten by many) and has the greatest amount of differences to the other poncho v8's.


Talking about big and small blocks can be confusing in some devisions. Its nice and simple with the small and big block chev but once you get into the other divisions its not always so clear cut

 

I built a 350 rocket motor for a friend of mines Olds a few years back. The motor had 11 to 1 pistons from the factory and it was a bad daddy when we got done with it. I agree with the other postings though. Chevy motors are a lot cheaper to build because of the vast amount of after market parts available for them. You can make more ponies for less money.