[2transams]

Hey all- here's a question for everyone. I just bought a 79 TA with its riginal tired Olds 403 in it. As I restore the car I want to do an engine swap to something with much more torque/hp potential. Any ideas what would be the easiest swap in regards to potential problems, i.e motor mounts, shaker assembly not fitting right (also height difference in the engines in regards to getting shaket scoop height right) ps problems, exhaust, ect? Maybe an Olds 455? Pont. 400 or 455????? Orshould I just build the 403? (yuck)LOL Anyone out there with experience in these kind of engine swaps??? Anyone with an engine for sale? LOL
Thanks, Rich

[2manyT/A'S]

Simplest swap for MOST POWER is late 60's - early 70's 455 Olds.

The 403 shaker/filterhousing will even work,although hood to shaker clearance is tight.

If it was MY car,I'd go with a 400 or 455 Pontiac.(just because it's a PONTIAC)

Engine harness will adapt.
Shaker & airfilter housing are different.

[Twissted]

Hey bud you can buy motor mounts from a couple places for the olds 455. This is exactly what I did and am still in the process of running fuel lines and other little things. I got an olds 455 for free but man has it been a lot of work. You can't run stock valve covers if you have roller rockers (my first lesson) and when you buy tall valve covers the ac condensor box does not fit. It might if you used a spacer plate and stock covers, I am not sure. The accesories will not fit with my style of valve covers either ( ) Aside from that, a few modifications to the oil galleys (olds over oiled the top end and spun bearings) and you have a big block that makes a ton of torque.

Wow with all that said I would build a 455 Pontiac if I was to do it again! Parts are cheaper and easier to find!!!!! Oh Well

My Heap of Crap (Olds 455 w/650hp on motor-spray will come later). Oh and it is dirty from having to move from KC to Denver!

[Iamtheonlyreal1]

I have am in the process of a Olds 455 installation..There are a few things that need to be worked out, but they are all relatively easy and doable...I currently have my 455 installed in the car..I am running the factory HVAC box, and the shaker hoods fits exactly right..

I have pics of my process and can advise about the process..I have dealt with all the processes that people have said werent worth the trouble...Anyway, If you would like to see some pics my email Address is Iamtheonlyreal1@yahoo.com

I would be happy to give any advise and pics of what the process was....

[jeepnsand]

whats up w/ the 403 olds motor mount brackets¿ i bought some after market brackets for a 1977 t.a.403 but thay don't bolt to the olds motor. am i missing some plate or somthing? what did thay do to make thease olds motors fit my pontiac bird.

[jeepnsand]

anyone know what thay did to make the olds motor fit in my 77 t.a. i got after marcket brackets but don't fit the olds motor am i missing somthing .

[Iamtheonlyreal1]

There is a pretty heavy bar that attaches to the 403 enging block...The engine stands bolt to that bar...There are three bolt holes on each side of the block just above the oil pan...That is where the Engine stand mounting bracket attaches to the block...

However, I am unclear about what you are trying to do...IF you are trying to put these engine mounts on a 455 there will be alot of altering...They will not put the engine at the right hieght or position...I currently have my swap completed..I do have pics, and I will see about getting them posted...I can email them if you email me your address...My swap looks a hundred percent factory,and the factory ac is still installed unlike the other swaps I have seen...I have completely torqued the enine in every direction, and I have no clearance issues...My Email address is... Iamthonlyreal1@yahoo.com


good luck...

[jeepnsand]

thanks for the info .i thought thay did somthing to get thease motors to fit the birds.
its a 350 olds motor that i'm trying to mount in my 77 bird.i just couldn't figure out what i was missing. the doner car was a 75 cutlass and saw no brackets or mounts that i could use from that car. and i knew pontiac put a 403 in the fire bird, just not that hip
on olds motors .all mine have been pontiacs.
anywho i just lowered the olds 350 down in the bird today and put one bolt through
the front bracket hole to the center hole of the block .bolted the tranny up ,just to see
how everything was going to line up .not to bad, does look a bit high and forward though ?: )- is the 455 olds block the same as the 350 olds block ?
if anyone has any advise about this subject please help thanks
jeepnsand

[raj]

Let's clear up a few things.

All 260, 307, 330, 350, and 403 Olds engines, AKA Small Block Olds, have the same external dimensions. All intakes, heads, tin pieces, brackets, and accessories are interchangable with a few functional differences. All the bolt holes are in the same locations. Cranks on every small block Olds have the same dimensions as well.

All 400, 425, and 455 Olds engines, AKA Big Block Olds, have the same external dimensions. All the bolt holes are in the same locations as well. There are 2 different stroke size on big block cranks for the record.

The difference between the big and small blocks is that the big blocks have about an extra 2" on each bank, thus the deck(and the entire engine) is about 2" taller overall.

F bodied cars that came from the factory with olds v8's all had a funky looking steel bracket about 1/4" thick in place of the mounts that originally bolted to the engine and sat on the frame pads. I've also seen the funky steel brackets on a few Olds diesel powered cars and post 1975 Venturas/Omegas with olds V8's. To the best of my knowledge, Olds powered F bodies have the motor mounts(frame pads) in the same location as pontiac powered F bodies. I read that(the frame pad location) on another site so it would probably be wise to verify this before going through with any swap of this nature, but I'm positive on the funky steel bracket thing and the small block/big block info. The real key to a pontiac to olds swap is to get a set of the 1/4" steel block mounts. I'd also assume the real important part of an olds to pontiac swap is get a proper set of Pontiac mounts for your Pontiac block. On an olds-to-olds or Pontiac-to Pontiac swap, I'd say use everything from the original setup you possibly could or locate identical factory pieces(or weld new mounts to the frame )

If you want to build the 403 or any post 1977 350 Olds, you'll run into a problem: windowed main webs. There are holes in the cast iron that leads up to where the crank mounts that make for a weak block. Still, the 403 has a really nice bore to stroke ratio and can be made into a nice street engine. To build it right, use some pre 1972 Olds 350 heads with casting mark 4, 5, 6, 7, and 7A since they flow better and have smaller chambers than the later heads. There are a few other mods you have to make to the earlier heads but none of them will run a whole lot more than $75 from a shop. If you use an Edelbrock Performer RPM intake for your 403, it won't clear the shaker hood scoop in an F body. The Performer will.

Big block Olds engines have the same dimensions as a small block as far as the bottom halfs go. You can bolt a big block oil pan to a small block engine and vice versa. You can also swap block mounted motor mounts. So, the thing to do in order to get a 455 Olds into an F body is---you guessed it---find a set of those funky 1/4" thick block mounts or just pull the ones off your 350/403 if that's what your F body originally came with. Since the big blocks sit higher than the small blocks, there are issues with the shaker hood scoop. I've heard of people modifying the base somehow to get it to fit, but another alternative is to find an original cast iron one from an early Toronado, although that'll hurt the flow of the intake. THere is a performer available for the 455 olds but no performer RPM.

There are tons of ways to build up Olds engines in T/A's I haven't covered. Look at a site called www.realoldspower.com or http://442.com/oldsfaq/oldsfaq.htm for more info.

[raj]

Double Post...

[Peti972]

i didnt know you could do that...thanks for the heads up! i was gonna get a weak ass 403 but now im gettin a 455...only thing is which one is the better option Olds. or Pontiac 455??

[Mr. P-Body]

The Olds is a tough and powerful engine. It does not respond as readily to performance modifications as the Pontiac. While it CAN be made to make good power, the dollars and effort are higher to get to the same level.

ALL the parts to install the Pontiac are "bolt in", where some of the tall-deck Olds stuff will be "custom" or using non-fitting stuff, hammered to fit (headers, mainly). Coin-flippin' time!

Let the Olds lovers begin their bashing...(:-

Jim

[raj]

Originally Posted by Peti972

i didnt know you could do that...thanks for the heads up! i was gonna get a weak ass 403 but now im gettin a 455...only thing is which one is the better option Olds. or Pontiac 455??

Depending on what your performance goals are, the 403 can be built to be a pretty stout engine. There's a guy on Realoldspower.com who swears by them. He has a 403 powered 1984 Hurst Olds and claims it will run low 12 second 1/4's. Here's a link:

http://www.realoldspower.com/phpBB2/...pic.php?t=2620

Remember the 455 Olds is 2" taller than the 403. It, of course, can be built pretty stout as well but I'd definitely check into shaker hood clearances and so on.

I'll respectfully disagree with Mr. P Body. Both engines have their strengths and weaknesses. Olds don't necessarily cost more to build, but there's definitely more after market support for Pontiac. Depends on the car. That being said, to answer your question I'd go with a Pontiac for a Pontiac car, but I can tell you a 455 Pontiac engine is going to run you double what a 455 Olds would to buy. There's also something to be said for going with an engine that's similar to the original and not have to deal with all that change over crap.

[Mr. P-Body]

raj,

Our experience has shown the poor valve angle of the Olds ("zero") leaves much to be desired when higher head flow is called for. The valve train is also quite weak and in need of major upgrades. It takes more cam and compression for the Olds to produce the same power from the same displacement.

One other drawback to the Olds is the rod bearing diameter. WAY too big! Of course, grinding it down to BBC dimensions is also commonly done with the Olds and Buick, as with the Pontiac. Offset-grinding can net you a few CIs, too.

There's no need for a 455 Pontiac. The 400 is a stouter block, and if "stroked", every bit, if not more effective than the large journal engine. 400s are much less expensive as cores.

Don't misunderstand me. I like the Olds just fine. Built MANY. Just being realistic here.

Jim

[raj]

The more common later Olds cylinder heads are junk. They can be dealt with with a die grinder and someone who knows how to port, but the earlier heads are definitely the ones to get. What I like about Pontiac is that the more common stuff is still good such as 5C or 6X heads. It's also easier to build a respectable compression with Pontiac V8's. I still like the Olds configuration of the intake ports and head design overall a little better than Pontiac, but valve spacing can be an issue with Olds heads. Pontiac will take slightly larger valves.

It would depend on the type of car as to which engine I would choose. For a street driver, it's tough to beat a G bodied Cutlass with a 403. None of the G bodied Pontiacs really compare to me since the 301's are a bit of a different engine alltogether from the earlier V8's. I've always been partial to the 1972 Lemans body style, and there's an issue with the factory exhaust manifolds on Olds A bodied cars that would make a conversion from a 350 to a 455 a PITA. Myself, I prefer the 73-77 Cutlass' over the GP's and Lemans' of that era along with the X bodied cars, but that's just me. For an F bodied car, I'd prefer a 455 myself since there's a little weight there and thus a bit more low end, but the 400's can be made to run just fine with that setup. I've never cared too much for the pre-67 cars.

I'm still a little new to the Pontiac scene, but if it's between 350's I like the Olds built 350 better myself. Between the 400 and the 403, it's a tossup but the 400 is definitely a more durable setup while the 403 would be just fine for the street. I'd take a 455 Pontiac over a 455 Olds, though. Piston selection is a definite plus for Pontiac. Just my opinion.

[Mr. P-Body]

The Olds 350 can be a far superior performance engine to the Pontiac, but.... At that CID, WHY? 350 Chevy stomps ALL of them. Anywhere 350P "fits", 400 and 455 do also.

As you're "new" to Pontiacs, be sure to understand how "different" they are. The strokers are the hot ticket. The main bearing in the 421/428/455 is just too big. Between the hole down the middle of the block being a 1/4" larger, and the increase in bearing speed, it's just not as desirable as the 3" main. Think "outside the box", and forget factory parameters. The engine was discontinued nearly 30 years ago, and we have learned a thing or three since then.

We have a few guys out there with 400s and 428s in their G-bodies. I'm sure there are 455s out there, too. Awesome combination. The G-body is the last of the "good ones" IMO, at least for a serious street performance car at a reasonable price.

Build and tune to make the most power possible under 6,500 RPM. While they CAN be built to withstand much higher, it's not cheap nor productive. Smokey said it best: "Don't REV it up... GEAR it up!" Take advantage of the engine's strong suit.

Jim

[Peti972]

sooo if you were to put any kind of engine in a 79 T/A, Pontiac 455 is the way to go?? or would you guys put a chevy engine in it?? im jus tossin up random crap...im a young muscle car enthusiast & i am new to engine assembly..so plz dont make fun of my car knowledge lol

[Mr. P-Body]

Chevy? Why? Craters are NOT what they''re cracked up to be. We've seen a mass number of "issues" with them. Like any other Chevy production engine, "blueprint" is necessary to make them live. Aside from that, it takes a big block Chevy to match the torque and horsepower of the Pontiac. A small block ain't gonna make it! (never send a boy to do a MAN'S job...) Weight of the big block will have an adverse affect on the road performance of the T/A.

No, a 455 is NOT the best way to go. The 461 "stroker" has more desirable parameters for longevity, while making the same level of power (maybe a tad more, as the "long rod" helps). The 400 block is significantly stronger and yields lower bearing speed. Cores are much less expensive, too!

FWIW

Jim

[bobzdar]

Originally Posted by Peti972

sooo if you were to put any kind of engine in a 79 T/A, Pontiac 455 is the way to go?? or would you guys put a chevy engine in it?? im jus tossin up random crap...im a young muscle car enthusiast & i am new to engine assembly..so plz dont make fun of my car knowledge lol

What do you want to do with the car? I'm road racing mine, so the Pontiac 400 was my best option, but your intended use of the car, transmission type etc. can influence which engine you decide to build. All of the Pontiacs 400 and up have the same bore so can technically make the same power as they all have the same airflow. The rest is just picking a stroke and rod length to match your intentions. If you want low rpm grunt, go for a 4.21 or 4.25 stroke, if you want higher rpm power, go for 3.75 stroke and if you want somewhere in the middle, go 4" stroke. Cranks are available in all flavors, so start with a good 400 block and you can have whatever you want. Ideally, a 4" stroke 6.8" rod combo would be what I'd build if starting from scratch...

[Peti972]

Originally Posted by bobzdar

What do you want to do with the car? I'm road racing mine, so the Pontiac 400 was my best option, but your intended use of the car, transmission type etc. can influence which engine you decide to build. All of the Pontiacs 400 and up have the same bore so can technically make the same power as they all have the same airflow. The rest is just picking a stroke and rod length to match your intentions. If you want low rpm grunt, go for a 4.21 or 4.25 stroke, if you want higher rpm power, go for 3.75 stroke and if you want somewhere in the middle, go 4" stroke. Cranks are available in all flavors, so start with a good 400 block and you can have whatever you want. Ideally, a 4" stroke 6.8" rod combo would be what I'd build if starting from scratch...

i am actually not sure as of yet....my Dad & I are planning on getting a 79 T/A by the beginning of this summer...my intentions is to get the biggest engine i can possibly fit into the T/A...on a post earlier somebody said i can fit a 468 stroker into it?? now my question is it's a 468 CID with a bigger crank?? and ummm...i jus want somethin' under my hood that roars even when it's idling....so maybe toward the middle...as soon as i get it & we start workin' on it, i'll be sure to post pictures & ask questions more often on this site...