My friend has a 6.6 Pontiac 400 out of his old 78 TA. He swears up and down its a big block 400. I don't believe they ever made a big block Pontiac 400, correct? Anyway, is this a good motor for the popular 400 buildup? Anything I should look for before I buy it? The motor is still together so I can't really look for cracks by the mains or anything. The motor will be going into my 84 Z28 HO A3. Thanks!

Jeffrey

 

It's not a "big block", it's a Pontiac motor. Pontiac didn't have "big blocks" and "small blocks"; all their blocks are the same critical dimension, namely bore spacing. They did have "tall deck" and "short deck" blocks, but not "big" or "small".

It's completely totally altogether utterly different from a Chevrolet 400. Absolutely nothing whatsoever, except maybe the spark plugs and a few distributor internal parts and maybe a couple of bolts, will interchange. It will not bolt up to your motor mounts, your transmission, or your exhaust.

People do swap them in though. There's people that make "kits" and various parts to make it possible. In fact, there are a number of Pontiac partisans on these boards, that will probably jump right in and tell you all about how you should do it. But what they're telling you, is not why you should do it; they'll be telling you why they would do it. 2 very different things.

Examine your reasons for doing such a swap. It will not be easy or cheap. It will more or less butcher your car, although it can be done in such a way as to be reversible. If you're one of the type of guys that has Pontiac motors like some of the other folks, has lots of parts for them, knows where to get stuff you don't have, etc. etc. etc., then it could be a cool swap. If you think it's going to be "cheap" somehow, you're in for a rude shock; you could get the motor entirely for free, in perfect running condition, and it will probably cost you more to put that "free" motor into your car than it will cost to buy and rebuild and install a Chevrolet 400. It will not make any more power than a Chevrolet 400; about the same, if you use equivalent parts. All the parts for improving it will be expensive. As it sits, it's not a very powerful motor; seems to me that it was "rated" at about 200 or 210 HP. Of course it will have 400 CID of torque; but then, any 400 inch motor will have about the same torque. Compare that to your existing 305's 190 HP (assuming that it's really the HO motor). And of course all sorts of people will say stuff about "well look at such and such motor from a 71 Firebird" or "well what about a 68 GTO motor" or whatever; that doesn't apply to what you've got. That 78 motor is the most smogged-up, crippled, weak version of the 400 ever made.

All in all, probably not a good plan. It's in the "if you have to ask, it isn't for you" class of things.

 

If it is a Pontiac 400, it's really not a big block at all. It's your typical B.O.P. block. 350's and 400's , 455's, 326's - all the same size block. So there really isn't a "Big" or "Small" block when your talking BOP.

400 Pontiacs are not an easy swap. You'll be tons ahead if you get a 400 SBC.......

EDIT - RB was responding at the same time I was! What he said too!

 

The 400's in the '78 Trans Ams are based on the same block as the 400's in the GTO's and early 70's T/A's as well. That motor is rated at either 200 or 220 HP and 325 ft lb torque. It could easily be taken to have the same hp/tq ratings as the older model engines, but it would be expensive. You can change the heads from the 4X heads to like the 671 or the 16's (which are the ones on the GTO's) which would bring the compression up close to 11:1 and swap out the cam for one similar in those engines as well. I don't know if the pistons and rods could handle it, but they should.

The engines in the 70 Firebird and GTO put out 350 HP and 420 ft lb of torque

 

my 77 T/A had the 6X-4 heads (lower cc version of the 6X heads)
I think it was rated 180 hp. The 78s were rated higher thanks to a better cam. Swap the cam, aluminum intake, or at least pre-75 quadrajet intake w/electric choke conversion. I think hooker makes shorty heades now, but get the headers for this specific swap. Scroll down the page, look at the 455 swapped in. good info there. The good thing about the smogger heads are that they already come w/hardened exhaust seats.

Also take into consideration that the HP numbers were changed between the older cars & the mid/late thirdgens. going from gorss numbers to net. very misleading :nono:

 

If everyone followed that mentality there wouldn't be anything such as an LT1 or LS1 or big block swap. Its called hotrodding.

 

Obviously I know very little about 2nd and 3rd gens! Thanks for the info! No way will I do that swap. Maybe a 40x sbc in the future though.

Jeffrey

 

hey b18,
does your friend still have that 400 available?

 

I'm failing to see the difficulty level in this engine swap. I'm doing this to my 86 TA.. All I've had to buy so far is motor mounts and a trans adapter to put a 700r4 on the back of my pontiac motor. The headers I bought off ebay years ago for the old 73 catalina the motor came out of. After you have a Y-pipe made up, all that's left is wiring it up.. pretty simple.. Hook up your ignition and your alternator. maybe a few sensors and guages and you're done.. Even with my very tall Torker Intake, it still all fits under the hood with a big air cleaner. Pics are coming eventually as I have everything back out for finishing, painting, etc. Going to be very pretty.


I just hate it when other people who don't have the skill or patience to take on such a thing will tell others not to do it either. that sounds pretty judgemental to me. " Hey buddy!! DON'T do it.. cause I KNOW I can't do it!!" What a poor attitude for this hobby.

 

You pretty much stated why it isn't easy or cheap - You have to buy things not needed for a SBC swap of the same CID, and you must fabricate things that are available that will bolt in with a SBC.

Assuming the person asking the questions does not have the skill or patience to do an out-of-the-ordinary swap is statistically safe. There are a bunch of 3rd gens out there that have been hacked up and never completed because the previous owner assumed whatever it was they started would be easy, cheap, and quick, and they turned out to have neither the skill nor patience - and often the funds - to see it through. My brother just picked up two such cars, between which he will be able to put together approx. 92% of a car, and we hear about it all the time on this Board.

A more accurate attitude would be, "Hey, bubba, just because I did it don't mean you can do it."

 

So far, I've not had to fabricate a single thing for this swap. all that I willahve ot have custom made is the Y-pipe to go to the single 4" pipe. The only thing I've had to really BUY as far as a special swap part is the trans adapter plate and motor mounts. both I got for less than $100.

If you buy the mounts, the adapter plate, and get a y-pipe made for your manifolds, well, that's all there is to it for a swap.. everything else is as easy as anything.. maybe even easier because of only having to hook up 3 other wires to be on the road and running.. Ignition, alternator and coolant sensor if that's what you run. Now.. if you want to go all high tech, etc with knock sensors, etc, well then go for it.. but as far as making a running car and an easy swap, there's really nothing at all to swapping in a poncho motor.


now.. then if you want to get real tecnical and talk about all the damage a poncho motor is going to wreak on your rear end, then I guess you have to spend some serious bucks beefing that part up...

but anyways.. If you ahve a poncho engine kicking around and need to put it in an f-bod.. it's pretty basic.

The problem here is that you just go ahead and assume they don't have the knowledge or skill to perform the swap. Just because you've run into some junk someone that actually proved they had no skill in doing these things, doesn't mean everyone asking abotu a swap has no skill and couldn't possibly follow thru with something like this.


Anyways.. burning up my lunch hour..

 

Okay, let's approach this from a different direction: There's a sticky at the top of this forum that covers this topic https://www.thirdgen.org/techbb2/sho...hreadid=252874 . Note the originator's choice for subject line.

Can it be done? Of course. Can the typical person on the street accomplish it? Probably not. Can the originator of this thread? Doesn't sound like he's going to tackle it - unless you want to talk him back into it.

 

heh.. forget it.. like talking to a wall... round in circles we go..

Some people just can't help but assume. Also, the sticky on this topic has VERY little information on the swap. BUT, I've already talked with a moderator as too WHY there's so little info on the topic in there. we are working to remedy that soon. But anyways, if you're just going to assume someone has no capabilities to tackle something, then don't bother posting.. Don't hinder the hobby. Why ont try some encouragement or some guidance besides "it's too costly and too complex for YOU to do so don't bother......" type stuff. And newcomers to the hobby gotta learn somewhere anyways, so nothing wrong with a little trial and error to help educate... I'm sure the guy who put the first poncho motor into a 3rd gen had NO idea how to do it and had to learn as they went... If someone wants to do something, let them do it.. if you can't HELP them do it in some way, why bother discouraging them?

anyways... I might as well be talking to the wind..

 

Someone who isn't capable of swapping a non-computer controlled V8 of another make (Pontiac or otherwise) into their car, when pre-made parts to do so are readily available, probably couldn't swap in another SBC successfully either! There is nothing to this swap.
Is it more expensive? Probably, but it depends on what you are comparing it to. Given the same amount of money, and assuming you had to buy each engine and bolt it in the car, there isn't going to be a huge difference.

 

"Anyway, is this a good motor for the popular 400 buildup?"

No, thats a good motor for the unpopular 400 buildup.

 

 

I suppose we can appear jaded and negative when questions of this type are asked. I guess that's because we see so many threads that say something to the effect, "I was told this swap was easy, but my car is in pieces, I can't figure out where these wires are supposed to go, and I need my car back. HELP!" So, rather than encouraging people we don't know to dive into a project, we tend to error on the side of encouraging them to know what they're up against before they start a project. Nobody can say how many people may have been talked out of something they could have accomplished, but there are numerous times people have realized there was more to it than they thought when they posed the question - sometimes they just needed the additional info in order to be successful.

We're here to help. I try to respond only when I know what the person needs - sometimes I respond because no one else has, and will have to admit I'm only speculating. In this case, I've never done a Ponco engine swap, true, but you're the one who mentioned fabricating, after all.

Peace. Swap on, bro.

 

I will agree with most of that. I would just like to try more to help them get to where they were going in the first place than to give up on the project all together. after all, they've come this far, why stop now. Most any engine swap you can think of or imagine has PROBABLY been attemted at some point. I would find it safe to say that there's gotta be infomation on almost any swap somewhere. Not to mention kits and brackets, etc.. things like the Volvo to Small Block Chevy conversions, Chevy V-8's in Jaguars, etc.. LOTS of older Chevy and GMC trucks were converted to Pontiac engines for the torque. Jaguar V-12's swapped to old fords, etc.. you name it, someone's swapped it into something. BTW, Anyone ever hear a Jag V-12 with open Headers? aaah what a sound. Those are fun motors to rebuild..... ..

Anyways, I apologize for getting beligerant (spelling). Just don't like to see people discouraged from the hobby. Hopefully soon enough therer will be a very informative article on this pontiac engine swap. I hope to contribute as much as I can to it with pictures, part numbers, etc.

OK... Done babbling.. Long live the car hobby and DEFINITLY long live those who have the guts to attemt something new and different.

Peace to you as well...

 

If you come up with a detailed, informative Poncho-into-3rd-gen swap thread, I'll gladly unstick the chit-chat above and sticky yours in its place.

 

Will Do.. consider it done.. give me a few weeks as I'm VERY limited on time right now.. Wife workin odd hours and such, so I'm stuck babysittin alot of week nights, but I'll for sure write up something and include a bunch of pics. part #'s, etc.

 

I don't think you'll find that even most of us who tend to discourage off-the-wall transplants, are doing so simply because we don't like swapping.

What we (or at least, I) constantly encourage people to do, is to understand up front, that especially in this day of emissions certification, a street-legal daily-driver swap is NOT a trivial matter. There's alot of difference between putting a Packard V-16 into a 32 T-bucket for car shows, and messing with your ride that gets you to work.

A swap is never cheap. The bulk of the cost IS NOT the motor that's being swapped in; and it's usually not the car it's going into, either. The money is in all the little things you have to do to make stuff hook up and work. For that reason, if somebody says "I got this F*rd 429 for free and I'm going to stick it in my 91 Camaro RS because a 350 will cost me $1200", he's fooling himself. It doesn't work that way.

You'll also notice that the people who are successful at things like potting Buick motors into these cars, have had Buick motors for years; have a stockpile of parts; know all the variations (or most anyway) that might be available, to make fitment easier; have friends with parts; know where to get parts; have done this sort of thing before, usually to an easier chassis (like maybe, A bodies, which might have come with a Buick motor), and therefore have sort of stepped up from a near-trivial to a little more daunting one; have tools such as fabrication setups, like welding, sheet-metal brakes, shears, etc. etc. etc.; and otherwise are a whole lot better equipped than most of the people doing the asking. They'll tell you all about how easy it was FOR THEM to do it; how THEY didn't have to buy (for instance) heads or manifolds or whatever; how all you have to do is use the this from a 73 Camaro, a that from a 67 Skylark, a something else from a 81 Cutlass with a 3.8, and so on, all stuff that a beginner wouldn't have the foggiest clue how to research. In short, you see answers that are all about why the answerer WOULD do the swap, not why the asker SHOULD do the swap.

Another thread you commonly see in these posts, is the "74 Olds 455" type of question. Well let me tell you something, I was working in the new car industry in 1974; and those motors SUCKED. The cars were slug slow, and drank gas like a fish. They were totally laughable as "performance" material. a 60s 6-cylinder car was faster. So you see the kid with the afore-mentioned 74 Olds 455, and somebody that likes Olds motors immediately starts telling all about the 71 HO W30 442 they had, and how a 455 is a great motor, stood the car up on its back bumper, never lost a race, and blah blah blah. OK fine. Problem is, the kid who asked the question DOESN'T HAVE a 71 HO W30 455; he's got a smogger turd out of grandpa's old sedan after it finally laid down and died. He's going to spend a year's salary putting that POS in his car, and he's going to ride the bus for 9 months of that year; and when he gets done, he's going to have a car that will get waxed by a bone-stock L69 or LB9 car, and it won't work for 2 days in a row without having to work on something because it broke or fell apart or whatever. Ouch.

Some of the swaps you mentioned are trivial. For instance, a Chevy V8 (big block especially) in a Jaguar. You do of course realize that the 70s Jaguars CAME WITH A CHEVROLET CASE TURBO 400, from the factory; and that you can make one phone call (or mouse click nowadays) and have a complete kit of every mount, nut & bolt, wire connector, exhaust part and everything else, at your doorstep tomorrow morning. Putting a Chrysler 440 into a third gen Firebird is a little different from that.

So remember those things next time somebody says their uncle has the 500 motor out of Gramps's 70 Cadillac laying out in their back 40, and the kid has wild dreams about yanking his 2.8 out of his RS and sticking that in there on a McDonalds job / college tuition budget. Encouraging him isn't in his best interest, or anybody else's for that matter.

 

LOLOL.. Some people just make me laugh.


the SMOGGIEST of smoggiest 455 engine will out do most stock 350's.. NOTICE i said MOST.... so there's no confusion about bringing up say a 69 LT1, blah blah blah.. 455 cubes is FAR greater than 350 cubes.. and a smogger 350, which is what even the best factory 350 TPI was in a 3rd gen, is far less potent than a "74 olds 455 smogger" in 73 the big 3 were trying anything and everything to bring down emissions.. but even still 455 cubes is 105 more cubes than a 350. if you even HAVE a 350 in your 3rd gen to start with. If you're trying to get rid of your 2.8 v6 engine and drop in a 350, you are going to plunk down just as much coin for a de ent 350 as you would MOST any other engine you want to put in your car.. and with one phone call to the right source, you can get an engine swap "KIT" for almost ANY engine.


There's only ONE reason Small block Chevy's are so popular.. they are the MOST plentiful block in the world. Hence it's the most commonly found engine or most commonly available engine on the planet. THAT's the only reason why you can put them in almost anything.. and WHY they are the more popular swap.


ugh..anyways.. this is pointless to some people. some people just DO NOT want to see someone else take on something they could not possibly do themselves. Love how they start going off on wild tangents to try to make some kind of point. If you don't want someone doing a particular engine swap, then DON'T let them work on YOUR car. If someone wants to do ANYTHING to their car, by all means, DO IT MAN!!. Go For it.. I got no problem with explaining to someone what a part costs or how hard it is to find, etc etc, but I'd still be saying GOOD LUCK and I HOPE you succeed in this swap, venture, whatever. I SURE as hell wouldn't want someone telling me I shouldn't bother cause it's WAAY too complex, too hard, too expensive, etc.. "what the hell do YOU know what I can/can't do or can /can't afford?"

Anyways...

Nuff said.

 

true dat. I'm just glad of all the f-bods, GPs, Bonnevilles, etc that came w/same engine are still plentiful, and the engine has an active aftermarket

Yea, ther are no kits that I know of, but there really isn't that much needed to make it work.


Swap on!!!!!

 

Okay, the Pontiac boys have a new sticky. It contains information, not flames.

swimster:
Cool your jets. RB has it right. He's not trying to discourage someone from doing what he's done, he's trying to protect a few people from themselves. The originator of this thread is probably one of those types (haven't seen him around lately). On those rare occasions when he's read someone wrong, he's backed off and provided the pertinent information.

And, just in case there's anyone out there that missed it, there's no such thing as an emissions-legal Pontiac 455 swap into a 3rd gen.