I was wondering how difficult it would be to swap a big block pontiac 400 into a firebird. I was just wondering because my friend would like to do this and i would like to help him as much as possible.

 

No such thing as a big block Pontiac, either it is a Pontiac, or it isn't. Same bore spacing on all of them. The only difference is deck height, but that doesn't make it a big block or a small block; just a tall deck or short deck.

It's a pain but not impossible. You'd need mounts, a BOP trans (some of the 6-cyl trans might have the same bolt pattern, I have no clue about that though because I have never touched a 6-cyl one of these cars), the exhaust is a totally custom deal from one end to the other, the battery needs to go on the other side of the car, etc.

There are people on this board who love Pontiac motors, and you will get lots of monkey-spank about how they're "superior" to Chevrolet motors, how they're "torque monsters", etc. etc. But in fact, they run no better or worse than a small block Chevy of equivalent displacement and flow, and they weigh a whole lot more. If your friend is dead-set on doing it, then that's one thing; but don't believe for a minute that it's easy, or that it will run any better than a Chevy 400 small block with equal heads.

Even if he got the motor for free, it will end up costing more than going out and buying a Chevy motor; and be about 100 times the hassle. Like I said, if for whatever reason he's already made up his moind, that's one thing; but even a "free" Pontiac motor will cost him more than he realizes to put in and get running, and he'll end up rigging an incredible amount of stuff because it was never produced that way.

Yes, I've had lots of Pontiacs over the years, more than most of the Pontiac evangelists here have had. My first one was a 59 Catalina. I think the newest Pontiac I can recall that I had was a 67, right in the heart of the 400 days. I'm not going back.

 

Sorry guys my son is using my name again.
Josh if u want to ask stupid questions get your own user name!!

 

Now is that anyway to talk to your son?

 

u r right zenger I shouldn't have said that I should of just knocked some sense into him with a bff

 

Whats wrong with wanting a Pontiac engine in a Pontiac? More expensive yes. easier no, results... worth it. Pontiac doesnt get the respect it deserves. Torque monster it is. Thats what gets you from red light to red light. More and more aftermarket parts are being made for these engines. To kick some butt at the track and open the hood to see a "Ponti-rag"... priceless. Chevys are a dime a dozen so why not be a little different. Depends on what you want to spend. Whats wrong with 9.30@151 on BFG radials on a street 76 TA. (that is with nitrous). And for what its worth... my 412 Pontiac is goin in 87 Camaro. Hey dad. let your kids have some imagination.

 

Nothing is wrong with putting a Pontiac engine in a third gen in fact I have plans to do it in the future. I love Pontiacs and I'm currently looking for a 421 to build for my 68.I then plan on getting athird gen bird to put the current motor in.

I however don't apreciate my son using my user name to ask vague questions that I could have answered for him.
Makes me look stupid and I have talked to him about it before.
Hell I am the one that bought this kid his first camaro and bought him a 350 4 bolt and headders when he was 15. iI also found him the third gen after he wrecked the 2nd gen and consoulled him on the swap. He is stuborn and didn't listen to my advice on several things that ended up costing him time and money . I would say thats pretty supportive.

What he really wanted to know ,or so he says,is has anyone done this swap?

 

Hey Chuck,
You're son may not be the sharpest tool in the shed but at least he's got the faster car.

 

HAVE U ANY PROOF BILLY

 

my only advice... hope his friend has a good job

 

Seriously though, Josh posted this because we were trying to go through what had to be done for a poncho V8 in a third gen. particularly if I could use a 700r4, I figured a motormounts wouldn't be a problem I think if I used some out of a second gen TA. I understand about the fuel, the other thing is I head there are some shorty headers for pontiacs now, that would seem to work out nice. I'm trying to think of any real sticking points, and can't come up with any, it sure seems easier than the V6 to V8 swap.

Bill

 

I keep bringing this company up...lol. Pontiac 400/455 swap into 82-92 F-body. Indian Adventures have the install kit available and headers for this swap should have been ready a week ago. Thats how I'm gonna do mine

 

I checked their website but didn't see anything other than an install kit in A or G bodies.

 

I'll shoot Dick Duclow an E-mail and find out whats up. Install kit is supposed to be available and headers were supposed to be ready by 1/25/03.

 

Install kit part #10776. Headers by Feb 28th, forgot to ask about price.

 

I have a few questions I wanna throw at you guys, first will my Pontiac motor bolt up to a 700r4, I don't think it will, but I haven't found an adapter anywhere on the web. Also what about the lock up feature on the tranny. Indian Adventures may make good parts but I don't think i'll be able to afford their headers, I thought the exaust manifolds could work out alright, but I'm not sure, I don't wanna get into this and find out I have to buy $500 headers. What about cooling, you think a typical 8 cylinder car radiator would be fine? the one i'm running now is MASSIVE, like at least a third larger than a stock third gen. I know how the fuel system would work. I figured second gen motor mounts. where's all my money gonna go. I'd like to hear specifics as to why this job would be so hard, not just I hope ya got a good job. I'm not committed to this swap yet. but I'd really like to blow the doors off some mustangs with my ancient motor

 

Jegs has an adapter plate for BOP engines to Chevy transmission, Part #555-60172... $54.99
Not sure but you may be able to use stock manifolds. Your V8 radiator should be fine. And I have heard of people using 2nd gen mounts but not sure either. Havent got my engine in car yet. Doing some miner alterations, aka the only thing stock is the timing cover...lol. If building a high powered 400 the problem will be hookin up. SFC's are a must and you will want to consider lift bars etc to keep from just spinning your wheels. Summit has the South Side Machine kit with SFC's Lift bars and driveshaft loop for $489.99. Also consider a roll bar or cage to help stiffen body. This will not pass E-check if you have that stupid law where you live. (I do). Will need to check into driveshaft length. The one thing that worrys me right now is if my tall valve covers will fit under brake booster. Not sure of hood clearence with my Holley 800 dp with 2" spacer so will need a cowl hood.

 

Hey 66GPman
Try this site
http://home.earthlink.net/-saawatson/

 

dammit... site didnt work
I have a member on my Pontiac board that has a 455 in a third gen. I E-mailed him with all your questions (and a couple of mine). Will let you know any advice he replies with. For any advice on building up that 400 check out Performance Years. Great message board for Poncho's. 6337 strong with professional engine builders and racers.:hail:

 

well i decided to come back on here to agree with bob on this one. i'm the guy from PY forums that has a 455 in my 83 trans am, and thats a link to my site up there. anyway it's ez to do no big deal to do the swap. way better then just stuffing a big block in there. i still run the same 3.23 gears the car came with and pull 1.62 60 ft.s with the same 30 year old peg leg rear end. all about what you know and how you use it. great thing about pontiacs are they make low end TQ. you don't have to run a **** load of gear to make one turn on. i run a stock cam iron heads and a performer rpm with a vac sec holley carb, a bunch of cheap junk in most peoples opinions. i was told OH man you need a gear, Oh man you need some bada$$ heads, OH man you need a ford 9" with a spool, you know what everyone can use what they want to get there i'll use my own way to get there. so far the weak little 7.5 rear end has made about 10000 passes on slicks with diffrent motors in the car 2 years of the 327 running a 150 NX shot running 7.80's in the 1/8 mile 1 year with a 305 with a 100 shot NX running 8.20's in the 1/8 mile and then the 455 in the car running 7.80's with no nitrous! so lets see

7.8 = about 12.17 but the 60 ft if the trany had been rebuilt buy some one who knew what the hell he was doing i should have ran closer to a 7.2 in the 1/8 that comes out to
7.2 = about 11.23 with no nitrous a stock cam 9.3:1 compression and a bunch of used crap. not bad for a street car!

the 305 ran 8.2's
8.25 = 12.87 with a 100 shot a big cam lots of compression blah blah blah you name it it had it. same with the 327 all the parts in the 305 came out of the 327 when i burnt a piston.

now if i had listened to the guys about oh just stuff in a BBC it will work i would of had to buy gears huge stall and a bunch of other crap to go with it, trust me i build big blocks for people all the time, they like rpms to make them turn on. for a street car a pontiac is the best way to go!

as for the rear end i'm sure i will break it, just don't know when then i will go with the 3.08 9 bolt i have and still fly!

--------------------------------------------------
L75 owns LS1's!

 

http://home.earthlink.net/~saawatson/


LOL bob you put in a - insted of a ~

 

HMMMMMMM, thats weird, true on the whole there is no big block pontiacs, all of them are the same 326-455 the deck height is the same on all of them too with the excpetion of the 303 rare racing engine the 303 and the 265 crappy late model motors. but the 326-455 share the same block size heads interchange the timing covers too, valve covers, cams, rods, ect.... the diffrents in the motors comes down to this. 326-400 have 3" mains and 421-455 has 3.25 mains the stoke on the 326-400's is 3. 75 in most cases there are diffrent ones in like the 50's the bores range from 3.7810 in the 326 to 4.1200 in the 400. now the 421 and 428 share 4.0 stroke and the bores are diffrent 4.0938 on the 421 and 4.1200 on the 428. the 455 has the longest stroke 4.2100 but the bore is just a tad bigger than the 400 pontiac by .031 with a 4.151 bore. there is plenty of guys boreing thier 400's .031 over and turning the mains down on the 455 crank and getting 455's out of thier 400's.

now with a SBC most of the mains 2.45 305's 350's the list goes on from there. but the 400 chevy small block has a 2.65 main journal and the 283's have 2.30 mains no one goes around calling the 283's small blocks and the 350's big blocks and the 400's even bigger blocks and then what would you call the big blocks? them dudes ARE BIG!

a pontiac sitting next to a SBC looks big, but they are not a big as a BBC i need to take a pic of a SBC head and BBC head and a Pontiac head sitting side by side the BBC head is at least 2" longer than a pontiac head. pontiacs are wide looking, the intakes are wide and the valley pan makes them look wider.

anyway just hope to help clear up some of the confusion of the mystirous pontiac motor. just look at them like FE FORDS all the same size from the little 352- 428's just one dang motor.

 

Thanks all you guys for the info, I was thinkin today would it be best to just pull the fuel pump off and use a regulator. or could I use both the electric and mechanical pumps, prehaps I can regulate the fuel down before the pump, and save pullin the mechanical??? You guys have convinced me I can do this swap, though it'll be awhile before I can.

 

thaks for popping in 83 Ta
Done in by a -
I too was thinking of combining an electric with a manual with regulator. Any advice

 

edited

 

no problem bob, i used to read this board like i read PY now, but i think diffently than alot of the people on here. and i have lost my password to diffrent user names and such too, i had to have the site send it back too me to post on this thread.

on my car we used a holley blue pump, but i have had the blue pump on the car since the 327 days. at our shop we have regulated down plenty on electic pumps using the holley carb type regulators.

the 700r4 might die behind a 400 pontiac, not shure. my 700r4 died the first pass behind my old 327 but it was a weaker 1983 tranny, i have seen 700r's hold up to alot of abuse. but most are well built. i would suggest a long tail housing th350, but i burned mine up on a fresh rebuild in one pass, then i had it built up alto clutchs koleen steels, extra clutchs. diffrent forward drum. $500 in just parts, if i remember right. if you have some questions just e-mail me or hit me up on aim @ THIRDGEN455. i'm on all the time.

shad watson

 

hmmm... maybe I should consider a th400 over my 350.

 

well basicly find someone who is a good rebuilder and understand that pontiac MAKE TONS of TQ. they guy who build my first one built all of my uncals race trannys th-350's and glides but they where for chevy motors. well the rebuilder raced chevys and thought the world of them and didn't think pontiacs made any power! i told him i wanted that dude to hold up to 1000 ft of tq he just blew me off and said ok man. well i had my friend SLOW77TA from PY forums build my tranny this time just like his, he runs a butler 472 and runs 10.90's in the 1/4 N/A and should hit some super low 10's or even a high 9 when he puts the nitrous to it. best pass is like a 10.30 so i knew his tranny would hold up behind mine. well when him and his father tore my tranny apart it seems as how the rebuilder never even had pulled the vlave body off, the stock selector plate was still there even though the guy claimed that he put in a shift kit. well now the tranny holds. it really depends on who builds it and if the cases is good to start with. basicly good fluid a deep pan a big cooler, and some good clutches will make one work. the stock clutchs just couldn't handle any power. after about 10 passes it looked like the tranny had 100k on it. the steels where burned bad! they just didn't hold. i just wished i hadn't ran the car on the street first and burned the tranny up, if i would have taken it to the track i could have goten a good E.t. and had a clue what it ran. hell it still ran high 12's on 5 clys basicly. not bad i just can't wait till the head gaskest get here so i can put it back togeater! hoping for some 7.0's 6.9's in the 1/8 with the new motor, the add the 200 shot to it when i get her all tuned in. can't wait.