Engine SwapEverything about swapping an engine into your Third Gen.....be it V6, V8, LTX/LSX, crate engine, etc. Pictures, questions, answers, and work logs.
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This is something i've been thinking about lately since my T/A is DOA..
my questions:
How much different are the engine mounts? any issues with anything there?
any other clearance issues? How much is the weight difference? my car allready sits too hight in the front.. lol this might be a nice way to lower it as well as gain a 500HP beast
the final Question...
If i find a Stock 455.. what am i looking at to get it close to 500 HP. i allready know i'm gonna have to toss in a decent cam, intake probably a 750 or bigger carb, headers and maybe a bit of P&P.. anything else ?
Thanks,
Dave
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1991 Z24 Cavalier 5 spd; P&P'd 3500 MPFI swap, BIG cam, stage 3 clutch, EQ/LT-headers, UDP other misc bolt-ons.
13.08 @ 105.5 MPH all motor
275 WHP/249 WTQ
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i bought the motor mounts from potiaction racing and had to make a plate to move the trans mount back 3 1/2 inches. i used a trans mount from the 77 trans am that i had. the stock manifolds dump in the same location as the original 350 did. there is no clearance problems except for the hood. the distributor is about 2 inches from the firewall. as far as what it takes to get 500 h.p.. well to each his own. mine is bored .030 over, a big streetable cam, holly 750 double pumper, and an edelbrock performer rpm manifold. not a whole lot of mods, but it makes 460 h.p. and that is enough for me ... for now.
the best price i have so far is 275$ to cut the ends off and weld in a new tube. some people i have talked to say this is too expensive... but it seems to be the going rate round here.
it breaks my heart but i am putting this monster up for sale... got to save the house. i can post more pics if any of you out there might be interested. i have over 5000$ in the motor/trans and other misc. parts. full set of auto meter phantom instrumentation. you can reach me at kross40@comcast.net.
I didn't read everything here but the early third gens with a TH350 or TH250? had longer driveshafts which should work as the TH350 and TH400 are the same length. All you will need is the bigger yoke and a conversion u joint. Should be able to nail one of those shafts at a wrecker for next to nothing. Nice swap man. Pontiacs are great engines IMO.
Originally posted by 87roc_t56 I didn't read everything here but the early third gens with a TH350 or TH250? had longer driveshafts which should work as the TH350 and TH400 are the same length. All you will need is the bigger yoke and a conversion u joint. Should be able to nail one of those shafts at a wrecker for next to nothing. Nice swap man. Pontiacs are great engines IMO.
my '82 came with a 200R, we had to cut a bit off the DS for it to work with the TH400...
__________________
1991 Z24 Cavalier 5 spd; P&P'd 3500 MPFI swap, BIG cam, stage 3 clutch, EQ/LT-headers, UDP other misc bolt-ons.
That car looks like it would be a blast to drive, sorry you are looking to sell it... even more sorry I don't have the money to consider buying it!
__________________ MadMax: 1983 Trans am- Alum. motown block, vic jr. heads/intake, 100hp N2O, canton roadrace pan, spec clutch, alum. flywheel/driveshaft, t56, LT1 rear/3.42 gears,C5 brakes, fiberglass/carbon fiber body panels, cage, rod end suspension, nowhere near finished.
El Meano: 1966 el camino- 3200lbs. 4x4, long travel link suspension, cross over steering, axle trusses. Looking to the sky and finding breakage or bumpstops springtime '08!
Originally posted by Kross4031 the torque are that i used
can you tell us something of the torquearm and setup you used, it looks like one for a 4th gen. Is it? what is it? I have seen it before I just don't remember where.
I had a caddy 472 I considered doing this once, I was going to use a TH350 though.
considering that if a 9 or 10 second foot brake drag car can use a th350 without failure then, hey why couldnt a 12 or 13 second car right?
And I figured out how to get 455. the bore on a 400 poncho is 4.12 . the bore on a 455 pon cho is 4.15 . the stroke and main journal size is the bigger difference. but i found a stroker crank on ebay with pistons and all for it. also, since the whole long block, and exhaust manifolds, came from an early 70's GTO, I'm thinking 90% sure they're 6X8 heads... which means really low compression with the pistons i want. I'll keep you posted on the blower i buy. also, I'd like some more info on the brakcets you had to make, Kross. I'll send more info tomorrow.
I'm really glad i traded somebody tires i didn't need for that "400". it turned out to be a 350. the heads say "6x" on em, but i didn't see any 4 or 8 anywhere, just a "gm3" on the right side. what does this mean? also, is there any point to building a poncho 350? I'm pretty dissappointed right now, but it's no biggy. at least i have a bunch of spare stuff, like accessories and a timing cover. wish me luck. we'll see whta happens.
Originally posted by flyitlikustolit it turned out to be a 350. the heads say "6x" on em, but i didn't see any 4 or 8 anywhere.
You'll have to scuff the small "pad" that I have circled in red with a peice of sand paper that's where the 4/8 cc code will be stamped in with a punch.
Last edited by SOLID LIFTER; 10-08-2004 at 08:52 AM.
Originally posted by flyitlikustolit I'm really glad i traded somebody tires i didn't need for that "400". it turned out to be a 350. the heads say "6x" on em, but i didn't see any 4 or 8 anywhere, just a "gm3" on the right side. what does this mean? also, is there any point to building a poncho 350? I'm pretty dissappointed right now, but it's no biggy. at least i have a bunch of spare stuff, like accessories and a timing cover. wish me luck. we'll see whta happens.
What r u gonna do with the 350?
If you want to get rid of it ,call me @ 770-446-9909 or 904-838-1207
Daryl
Originally posted by flyitlikustolit I'm really glad i traded somebody tires i didn't need for that "400". it turned out to be a 350. the heads say "6x" on em, but i didn't see any 4 or 8 anywhere, just a "gm3" on the right side. what does this mean? also, is there any point to building a poncho 350? I'm pretty dissappointed right now, but it's no biggy. at least i have a bunch of spare stuff, like accessories and a timing cover. wish me luck. we'll see whta happens.
That sucks dude. I'd sell the 350, and go to Pull-A-Part off Moreland and get a 400 or 455 short block. Thats where I got my 455 shortblock ($50), and my TH400 ($50). If you want to be sure of what you're getting, there are markings on the side of the block but they're sometimes hard to see. Just pull off the intake and valley pan, and look down in the lifter valley. "50" is 350, "00" is 400, "55" is 455. You should be able to easily find a 400 or 455. My 455 was in a Pontiac Grand Prix SJ, but they're fairly common in the big cars.
Originally posted by LT1guy If you want to be sure of what you're getting, there are markings on the side of the block but they're sometimes hard to see. Just pull off the intake and valley pan, and look down in the lifter valley. "50" is 350, "00" is 400, "55" is 455.
Originally posted by RB83L69 Looks good so far....
But if I may be so bold, it's not a big block; it's a Pontiac motor. Not that the block isn't big; it's just, there's no such thing as a "big block" Pontiac. Either it is a Pontiac motor, or it's not a Pontiac motor. The bore spacing (the thing that sets a "big block" apart from a "small block") is the same on all their motors; even the little 151 4-cylinder has the bores on the same centers as a 455.
Yup, the first "modular" motor design.
Chevy guys get hung up on the lingo because of the big cube numbers. I hear this all the time. "Yup its got a pontiac big block..." the meaning is understood. Pontiac guys know what they mean though.
So here's a trivia question: are the buick and olds v-8s big blocks and small blocks?
Originally posted by LT1guy That sucks dude. I'd sell the 350, and go to Pull-A-Part off Moreland and get a 400 or 455 short block.
If you can build a 350 chevy you can build an equally powerful 350 pontiac. Car craft and Hot Rod both had excellent articles on this a couple years back. This is a good engine and has some design pluses; Spark plugs are above the headers and Intake can be removed without pulling the distributor making maintenance and swaps much easier.
The bore to stoke ratio will also let the 350 pontiac rev higher than it's bigger brothers. Yes you can make the big cube motors rev but not that's not cheap to do. Keep in mind the big pontiacs were built for LOW RPM TORQUE not high RPM horsepower. Remember the sizes of the cars these motors went into.
Now if you want a torque monster the 455 is the way to go. expect to spend $$$ on good aftermarket; heads, crank, rods, cam & pistons to get this thing to rev or make any power past 5000 RPM. The stock parts are not up to this task.
Nothing against 350 Pontiacs...just that if you can gain 105 cubic inches for an additional 50 bucks and a couple hours work, IMHO its worth it. Face it, thirdgens are heavy, they need a good torque motor...which is the attraction of a 455. They don't need to rev to the moon to make good power. Dollar for dollar, if you're talking small cubic inch, high revving engines, the Chevy is still the way to go. Not to say that you can't build a powerful 350 Pontiac...you can...its just going to be far more expensive than a small block Chevy. The 455's parts are more expensive than a SBC as well, but considering the cost of a good core here ($50 vs $5-600+ for a big block Chevy) and sheer cubic inches they are a bargain. One of the best things Pontiac ever did was the one block type, as far as interchangability and stealth go, but it really does hurt the popularity of the 350s, esp considering that 400s and 455s are so common (at least here) and so easy to swap in place of a smaller motor.
Originally posted by LT1guy
If you want to be sure of what you're getting, there are markings on the side of the block but they're sometimes hard to see. Just pull off the intake and valley pan, and look down in the lifter valley. "50" is 350, "00" is 400, "55" is 455.
dude, all the 400s I had had the 400 cast into the outside block, by the front freeze plugs. No need to pull anything off, jsut look from under car if still installed.
Originally posted by Project: 85 2.8 bird dude, all the 400s I had had the 400 cast into the outside block, by the front freeze plugs. No need to pull anything off, jsut look from under car if still installed.
true, but my reason for saying that is that a lot of times you can't see the markings in the car in a junkyard, due to exhaust,motor mounts, accessories etc in the way, dirt and grease buildup, etc. It takes about 5 minutes to yank the intake, and lots of times they're already gone anyway.Id much rather do that than figure out how to get under a car in a 'yard.
There are plenty of parts around to turn a Pontiac 400 into a 455. Pontiac produced more 400s by far than any other engine, so it should be just a matter of picking up a 400 block and getting the crank kit. The 400 has smaller mains than the 428/455, so you cannot use a stock 455 crank in a 400 block. The 350 does not have a thick enough block to go to 455, and you simply can't get near as much HP/$ with a Pontiac 350 as you can with a Chevy, simply because there has been more R&D done, more parts are available, at cheaper prices. And the Pontiac 350 is also somewhat heavier then the Chevy.
However, the Pontiac 400/428/455 are exactly the same dimensionally as the 350, and are only about 10 lbs heavier. They are torque monsters, and if built correctly are very awesome engines. For cheap, go with a SB Chevy. For all out performance, get the 400 Pontiac block and build a 455 out of it.
I have a couple options open, and I'm gonna check those heads again. also, a membr on the board wants my 350, so I may be wheeling and dealing to get rid of it, if nothing else to get a 400 block or something. we'll see. Thanks guys!
__________________ (Deceased)1984 Firebird Hard Top, 327cid V8, THM 350 w/Shift Kit, Stock "One Tire Fire" Rear End, 16 X 8 Formula Wheels w/245/50R16 H Rated Tires, Plethora of goodies under the hood, Manual Windows/Locks... 12.91 Best run on G-Tech.
(New Born)1984 15th Anniversary TA http://www.cardomain.com/memberpage/717952
what exhaust manifolds did u use and what oil pan did u use . Im seriously thinkin about doin the swap since my dad has a 400 i might buy and he also has a turbo 400. So i need to know these things. Thanks.
[quote]Originally posted by RB83L69
[b]Looks good so far....
But if I may be so bold, it's not a big block; it's a Pontiac motor. Not that the block isn't big; it's just, there's no such thing as a "big block" Pontiac.
So you're saying that the 455 SD and 455 HO are not actually the same block as a 454 Big Block Chevy? We had a Montery Jet Boat with a 455 Pontiac, and I swear that motor looked way bigger than the 350 in our Sylvan Ski Boat. Either way, stuffing a 455 (of any size) in a 3RD-gen Camaro is freakin' bad-to-the-bone!
Originally posted by nolanr0413 what exhaust manifolds did u use and what oil pan did u use . Im seriously thinkin about doin the swap since my dad has a 400 i might buy and he also has a turbo 400. So i need to know these things. Thanks.
I have seen a few with stock manifolds; one I looked at at the TA Nats had RAIIIs, but I'd bet nearly anything other than maybe the long branch style would work. All the oil pans are rear sump, so you shouldn't have a problem with any stock pan I have ever seen.
Originally posted by nolanr0413 what exhaust manifolds did u use and what oil pan did u use . Im seriously thinkin about doin the swap since my dad has a 400 i might buy and he also has a turbo 400. So i need to know these things. Thanks.
I have seen a few with stock manifolds; one I looked at at the TA Nats had RAIIIs, but I'd bet nearly anything other than maybe the long branch style would work. All the oil pans are rear sump, so you shouldn't have a problem with any stock pan I have ever seen.
sorry i have not gotten back sooner ... i have been away and i for some reason am not getting alerts that there are new posts. i used a stock oil pan . and stock manifolds off an early 70's GTO.
So you're saying that the 455 SD and 455 HO are not actually the same block as a 454 Big Block Chevy?
No the SD and HO are not anything close to a 454 Chevy. The only pieces that would interchange or remotely fit are the distributor cap and rotor, thermostat and gasket, Qjet and gasket, and the gasket for the fuel pump but not the pump cuz the Pontiac had a much shorter actuator.
SD(73-74) and HO(71-72) are both round port engines, the SD had forged rods, HO had cast rods. The SD had some other unique differences including the distributor OD, and provisions for dry sump oiling.
As far as the Big block small block debate, what it shows when you say big block Pontiac simply means you are clueless as to what the differences are due to being a Chevy or brand x guy. Not that you are stupid or something, just not into the uniqueness of the Pontiac engines. Pontiac had some forward thinking desingers and some aspects of the engines are far superior to other engines. Still they arent being made anymore and the loyalists such as myself are a rabid bunch to mess with..lol.
Someone posted a question as to Olds and Buick engines being small or big. Yes both have small and big. Olds big blocks 400/425/455 had letters on the heads and a taller slightly wider deck than the small blocks 307/330/350/403 that had numbers on the lower corner of the heads. Buick also has big and small engines main differences apperance wise are width and height of the engine. They all appear similar as far as olds and buick, but there is a size difference and quite a few internal changes.
Pontiacs use nearly all the same parts inside and outside. Its easier to say what doesnt interchange than what does. A little known fact about Pontiacs is that they arent much heavier than sbc, are only an inch longer and actually narrower than a sbc with non block hugger headers, making them fit into almost any place a sbc will fit and provide quite a few more cubes for nearly the same money, unless you go the cheapie route on the Chevy. Quality parts cost about the same, some are cheaper for Pontiacs than Chevy. Its all relative and depends on what you like and what you know.
I have access to an 82 Camaro and I have an extra 455 that needs a bit of work but is rebuildable. We been thinking about it, once the 79 is finnished. This looks easier to do than I thought it would be. Yes Travis I like it!
Sorry for being long winded and bring up a somewhat old post.
does anyone know who makes a forged 4.21 or 4.25 stroke crank? all i see are the cast steel 4.25 stroker cranks. I see forged H-beam rods and forged pistons though..... what gives?
aren't stock pontiac rods cast steel ?(assuming they weren't forged from the factory)?
I have a 400 block, rods, and pistons. in order to make 455+, i need to get diffferent rods, because i need to get a different crank... one with 3" mains and 4.21" or 4.25" stroke. Is this correct? I'm trying to figure out what to keep, or what to sell. I may sell everything but the block, who knows.
and on a side note, Does anyone need a 455 crank? i have one in great condition, I'm not going to use it because I'd have to turn down the main journals to fit the 400 block i just got. if not, I'm gonna offer it on ebay.
I was talking to a local road racer friend of mine, George Segal of Yank Tanque Racing (he runs a replica of the 70 Firebird of the Titus team in the historic series; there was an article in High Performance Pontiac about him recently) about the whole crank situation for Pontiacs, and he says the stock Pontiac cranks have been fine in his experience (no breakage). The rods definitely should be replaced, though. I don't think there is an aftermarket source for a steel crank for a Pontiac (all the Eagle ones are cast).
For that reason, I'm leaning towards reusing my stock 455 crank, though lots of people use the Eagle ones from Butler and others with good results. With all the new parts becoming available for Pontiacs...at least three different brands of aluminum heads, iron blocks, aluminum blocks, etc...hopefully someone will start making forged steel cranks soon.
so wait..... who all makes stuff for ponchos? There's the IA blocks, which i thought were iron, there's edelbrock heads, and eagle pistons, rod, and cranks. that's all.... I thought.....
also, while i would love to use this crank, I don't want to turn the mains down because the I'll have bearing fitment problems (i've heard), and It's also cheaper to buy a new steel crank with 3 inch mains from Eagle. I'd rather just buy all new internals, and know it's gonna fit right. thanks for all the help so far.
Originally posted by flyitlikustolit so wait..... who all makes stuff for ponchos? There's the IA blocks, which i thought were iron, there's edelbrock heads, and eagle pistons, rod, and cranks. that's all.... I thought.....
also, while i would love to use this crank, I don't want to turn the mains down because the I'll have bearing fitment problems (i've heard), and It's also cheaper to buy a new steel crank with 3 inch mains from Eagle. I'd rather just buy all new internals, and know it's gonna fit right. thanks for all the help so far.
Wenzler, KRE , and Edlebrock all make aluminum heads, Butler is coming out with an aluminum block (and copies of the RAIV heads and intakes, but thats more for resto guys), Edelbrock just came out with a Super Victor intake with injector bungs predrilled for EFI (rumored to be making a full retrofit EFI kit, like they have for other popular and not-so-popular (SB Mopar for example) engines very soon), March makes serpentine pulley setups...there is more that I am forgetting. If you don't already, get a subscription to High Performance Pontiac...that way, you'll get all the updates on new Pontiac parts that you'll neve see in the other magazines.
In your case, I'd probably just use the Eagle crank. Butler wouldn't be pushing them so much in their ads if they were junk. I'd really prefer a steel crank if I could get it, since my 455 is likely not going to be naturally aspirated.
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