I just purchased a 1968 Pontiac Firebird. The main reason I bought it was that it was 98% rust free, all Original panels, floors are rock solid, it's been in dry storage since 1994 and before that spent its life under a car port. The reason I could afford it was the one repaint that was done in 94 was done horribly, all of the seals, etc are dried out, and it's a base 250 six car.

Supposedly the motor was rebuilt recently, including a bore and new pistons. The guy I bought it from couldn't get it running right and it runs like crap - part of the reason being the single barrel is pouring gas from everywhere and it appears to be missing at least one vacuum line (PCV?) but I can't seem to find jack squat on parts or resource material for these motors other than some online pics of pretty looking motors. Simple crap like firing order and buying a fuel pump and new motor mounts.

Where can I find an online source or book on how to work on/tune one of these motors and what parts cross over with the Chevrolet sixes?

I'm not a complete idiot. I have a 65 Mustang with a very good running 302 and a 1967 C10 with a 350. Very familiar with V-8s and their set-ups. A little clueless here. I'd hate to toss a good motor (compression test soon), but if I can't find crap for it, I have a Pontiac 400 that can go in it's place.

Welcome! There are a number of OHC members on here, they should pop up. I know some parts are hard to find, but most seem readily available.

I also believe there is a Pontiac OHC forum (separate from this forum)

Sorry, I don't know a lot about them, I have all V8 'birds. But this site should help you hit the ground running. (pun intended)

Here is a link to PY's forum as well:

http://forums.maxperformanceinc.com/forums/forumdisplay.php?f=496

Welcome aboard. Here is another SOHC site with info.
https://www.tapatalk.com/groups/sohcsix/

Wow, lots of great info but the lack of parts is definitely disheartening... my problem is I have a 400 that can go in the car...

Doesn't sound like a problem to me. More of an opportunity!

Same old universal problem, time vs. money. It's looking like I'll need at least a grand or more just to get the six running right, and I know I'll eventually want more power... the 400 needs to be rebuilt... I was hoping to enjoy the car as a six for a couple years while I redo suspension, interior, and get my 400 rebuilt. Lots to think about...

My dad also has a 428 he claims I can have, but it too will need a mild rebuilt before it can go into a car... then I have all my C10 friends telling me to LS it

We'd all recommend keeping it Poncho!

The 400 is likely the cheapest to rebuild. And parts are readily available.

There is info and parts out there, as stated check the forum here:

https://firstgenfirebird.org/forums/ubbthreads.php?ubb=showflat&Number=3415&page=all

Also check with Clifford 6=8, I used them years ago to hop up a straight 6 chevy in a 65 custom Van, no one could touch me, they couldn't believe it was a 6 and I got well over 20mpg :

https://www.shop.cliffordperformance.net/Pontiac-OHC_c12.htm

also check Rockauto:

https://www.rockauto.com/en/catalog/pontiac,1968,firebird,4.1l+250cid+l6,1249220,fuel+&+air,carburetor,5904

and Kanter:

https://www.kanter.com/content/Pontiac/kanter_Pontiac_1968_Engine_Parts_155612.html

and this is the history of your engine, please keep it, it's a great engine

http://www.ohc6.com/history.html

Interesting note about your engine:

In 1968 the ohc6 was stroked to 250 ci with an increase to 175 bhp for the base ohc6

175hp in a Firebird is not too shabby, plus the torque

Finding parts isn't that bad but you have to be patient. I just rebuilt my cammer, so it can be done. One person you want to get hold of is Jerry Woodland, he is out in Utah (Google him). He carries abut every part you will ever need, he is reasonable on price and very knowledgeable. A lot of cammer owners will add Sprint parts (4 bbl carb, cam, sometimes a new head, etc.) to their base OHC, happens all the time.

Clifford was the first place I went. Definitely interested in their intake and dual exhaust header. Thanks for all the places/people to check out! I felt a little hopeless for a while there! Please keep them coming if you know of more. Google has been less than helpful. All I get are pics of motors and ads for 250 Chevrolet parts.

No decisions yet. I'm a few weeks from completing a 9 year renovation on my house (inside FULLY redone, exterior has new doors, windows, and roof) and I'm finishing up the siding and new soffit/tin trim. I did all of the work except the upstairs windows, roof, carpet, and countertops. I'm finally building a 24x40 shop this fall/winter.

I'd like to get the Bird running so I can cruise it. I'm just trying to figure out how to do it so I'm not "double spending" on the same parts - like I always do

Pics are from 2009 when we bought the house and last week. Please ignore the Corolla, my wife saw the error of her ways and has rolled in a Mustang the past 8 years. Kind of excited about another project, especially one of my dream cars, with the house done, and hopefully the shop won't take forever, I get to work on cars again!

Houses are never ending projects, we bought a fixer upper too, saved at least 100k, too many suckers pay way too much for homes in my area and it jacks all prices up, all the fools that bought 800k homes are now stuck with them.

It's crazy how $ homes are in some areas... you can literally buy a mansion on 10 acres or even a farm here for 500K or less. Our area has grown though, my house has appreciated +/-75K on the past 9 years. We're down to only owing +/-60K on it

Not to change your mind, but I have heard the stock Sprint 4bbl manifold actually flows better than the Clifford. Don't have any proof other than what I heard. FYI, you see Sprint manifolds on EBay all the time

What search terms are you using? I'm seeing zero.

Things like this.
https://www.tapatalk.com/groups/sohcsix/clifford-4-barrel-vs-factory-4bl-t2197.html

Update:

I was using the wrong search terms. If anyone else is interested, service manual for 67 and 68 birds:

http://thefirstgensite.com/html/P67svcmanual.htm

http://thefirstgensite.com/html/68smi.html

I think I've figured out why my motor ran like garbage. I was told it was rebuilt (I took that with a grain of salt) but apparently it really was... but back in like 1994, not recently.

So I ran a compression test. Good compression in 2 cylinders, like 80 PSI in a 3rd and +/-30 PSI in 3. No wonder it ran like crap. I was highly considering pulling it and selling it because of the cost of parts, etc, but I put my borescope camera down the cylinders and they looked brand new... hmmmmm. Adding oil did nothing to help compression, so probably not a bottom end issue. So something in the valve train/head. Pulled the cam housing and the head. I found that 2 lifters were stuck in their bore and one lifter was broken. IN ADDITION to that EVERY SINGLE hydraulic lifter was STUCK in whatever their last run position was probably 20+ years ago. And I mean stuck good, like I had to pinch it in my bench vise to get them to pop and even after that they were still pretty sticky. Ordered 12 new lifters from Kantor and they move free/easy.

The intake valves were also pretty sticky. I cleaned all the valves, lapped them, and I'm currently waiting on my seal kit to reassemble. I have high hopes this engine is going to run really well.

Cylinders 2 and 3 look almost like they've never fired since the rebuild. My dad and I think the motor was rebuilt in 1994, either something happened, or the car just sat, but it basically hasn't been run since then. The guy I bought it from probably thought he could just do some stuff with plugs and timing and get it going, he couldn't, so he kicked it down the road to me.

Also, if anyone was wondering... I finished the house

Building a 26x44 shop in the spring.

Snow? Looks like you need to move further south.

Yea, not a fan, I moved away from rural NY 20 years ago to escape it (I lived in the area south of Buffalo that's always on the news for stupid amounts of snowfall, most of my family is still there), and over the last few years my area of SC has been getting 2 to 3 snowstorms that drop a dusting to a few inches.... one last year was about 8"! When I first moved here, it never snowed, maybe a dusting or an inch, every few years, but that was it. This storm only dropped about 2" on us, but a couple hours north into NC they got about 10"!

It's rained almost the entire fall/winter so far, so these have been the best pics I've been able to get.