I have ask in another thread out buying a complete rebuildable engine and this is just a follow up to "what to do".

I found a 455 H273, YX, 485428 complete engine minus the carb and 4X heads. Needs rebuilding. The rebuilding is no problem.
$500

The second choice is a 68 YC motor that I was told is a 400 2brl.
with #15 head, not sure on the heads that is the number on the head where the other one says 4X. Said it ran but knocked. I can't see the back of the engine so noe build date or casting #.
I looked for numbers for this 68 motor and I can't find a yc 400.
All I can find is a 455 YC
$300

I have a 78 400 short block that is rebuilt but I have nothing else to put on it so I need a complete junk motor just to finish
it.

4th option, build a chevy small block and move on with my life.

This Firebird engine thing has me baffled and I need opinions from you guy that are in the engine "know".

Thanks for you help.
Eldon
Texas

The 455 sounds best..

The YC motor can be 67,68,69 a 400 (big car) 2 bbl auto trans. Could be a 70,71,72,73 455 or a 74 350 It all depends on the date code and casting number on the rear of the block. 15 and 4X are typically 455 heads with I believe 15's being used on 1971 400's.

There is a difference in compression/chamber size between the 15 and 4X. There were 3 or 4 different chamber sizes of 4X and 2 or 3 different sizes of 15's. Maybe why that 400 is knockin'.

Please don't go the SBC route. Something about that whole concept seems so wrong...

The '68 #15s are small valve, not much liked.

I second the 455. You don't need to "build" it for a Firebird, just rebuild it.

True..you overbuild a 455 in a light car as ours, good luck getting it to the ground.

Well all of you sound like you are pretty sure about the 455.
That is what I was thinking and the sbc did feel wrong.
What do you think about the price? Does $500 sound right?
What carb was supposed to be on that engine.
Thanks
Eldon

1974 455 250 HP YX A 8.0 067 4X 1-4 7044262 Block Casting # 485428

Carb was QJet 7044262, though any properly calibrated QJet will function just fine.

Heads will let you run 87 octane with no knock. If you want a little more power, change the heads and cam.

$500 is fair if the block is good and rebuildable. It would be good if the heads were a little more desirable.

$500 is very fair..the block and crank alone probably $7-800.

I have a set of #96 heads that would be real sweet for that 455.

I am planning on this car being a fun drive around car not a street racer or drag car so I would just build the 455 stock.
So I bet even the 4x heads would be more than fine for this car.

The guy selling the 455 said he will garantee the engine a good rebuildable engine.

Thanks
Eldon

The #96 heads would get you 9.5 to 1. very nice streetability without having too much. Depending on which 4X you have, you could be as low as 8 to 1 compression. The 74 455 heads are 114 CC which is right around 8.2 to 1. That would be one dog of a rebuilt motor..But hey, what do I know, I only rebuild motors.

Somebody else chime in on this. I would hate to see disappointment on a rebuilt motor with 8-1 compression.

If you don't know how to use the gas pedal, 8.2:1 is okay. You'll burn gas, the car will drive.

But if you like to enjoy the drive, bump 'em up along with the cam. 96s or similar are perfect at 96cc +/-.

Think I did say this a couple of posts ago...

6-9th line down...Not recmmending because I want to sell them, recommending them because they are well suited for what that motor will optimally run at.

http://cgi.ebay.com/ebaymotors/1970-PONT...sspagenameZWDVW

Quote below is from from Wallace Racing regarding Pete McCarthy's dissertation regarding Pontiac Heads. Pete McCarthy is well known in all aspects of Pontiac engine building and building engines to stock NHRA specs and getting the most out of a "stock" engine.

"I'm sure our readers are quite capable of drawing their own con­clusions with respect to some of these heads. I cannot resist the temptation, however, to list a few of my own opinions (see “Pete's Picks"). Whether you agree with these assess­ments or not, I would imagine that most Pontiac die-hards will find the numbers researched to be of great interest".

"Best low-compression D-port head No.96(1971)"

I have two pairs of 96's because I was building a 455. I am keeping one set, the other pair I am selling.

96's on a 455 would be a good fairly inexpensive package. Personally I'd build the 400 though. Just how many cubes does one need for a fun driver?
I know, never enough for some
The 400 has 3" mains, will rev better, stronger block, if you want cubes you can always put a stroker kit in it.
It may just be me but with everyone putting 455's in Firebirds it's getting all to common so that it's nothing special anymore. Kinda like all street rods having 350-350's intalled, boring. Put a 4" stroke crank in the 400 and build a 428, or just build the 400.

if banshee has a set 4 sale..you'd be money ahead to get them then to have another set rebuilt.

i tried to save some money and just have my stock heads rebuilt. ended up being 875$....i think cause there arent that many people really good at rebuilding pontiacs. if banshee has been doing it for 20yrs he proabbly knows what works best for cheapest.

Don't sweat it Eldon, things get twisted on this site quite often.
It's been suprisingly calm lately. If you had the time, room and money, I'd get both engines. Build one and store the other. You could always put the 455 crank in the 400, but stroker cranks are getting cheaper than machine time anymore. Ohio Crank I think even makes a Cast 3" main stroker now, much cheaper than a forged.
But a straight forward stock 455 build with 9.5:1 big valve heads will be a good torky engine with little mods needed. Cheapest bang for buck for sure.

"some" editing done....

Sorry that you got caught in some "insider trading", Eldon. Banshee (Tom) is a great guy and will help you out a lot.

On the engine side of things, having a higher compression ratio helps with power and with fuel economy. With decent tuning you can still have a good performing and reasonably efficient engine with 8.0:1. A couple of recent examples: tow vehicle BBC 454 w/7.8:1 resulted in 500 ft.lbs of torque and 402 hp at 4700 rpm on the dyno; a budget street driver Buick 455 w/7.5:1 that ran mid to low 14's and got 18 mpg (US).

I'm sure a Pontiac will do the same if not a little better! But why not build it better if you have the opportunity! The heads that Tom has will get you more torque, hp and mpg for very little extra cost.

I'm helping my son with his car project and we just picked up a stroker crank (cast steel) from Eagle for a different brand engine for about $100 more than it would cost to have the original crank ground! We're in one of those Golden Eras for performance parts!

Bjorn, you 'aint no fun.

Bjorn could edit out the Civil War...... Don't Tase me BRO!!

thats not what SHE said!

and WWII

now back to topic

OK!
Eldon,
Another option you could consider is to buy an already built engine that someone lost interest in. With what it costs to rebuild an engine you could be far ahead in time and money.

Or, if the components or workmanship are not up to snuff or not a good match, you could end up spending a lot more on an abandoned project. You have to know your sources.

Yes. It would be best to buy it running or from someone that has deep roots in the hobby that could verify what parts were installed and also heard it run. I know of a stock 68 400 like that. At $2000 I think you would be hard pressed to buy the parts and build it for that amount.

...and you can't compare the cost of rebuilding a chevy 350 to a Pontiac 400. Our engines aren't as common as the chevies. Parts, and options, and competent rebuilders are not as readily available.

OK, I now am the proud owner of a 74 455. I am going to take a breath and study up before ordering all kind of performance parts to rebuild this. I will be looking at heads first.
On my heads over the #8 cyl. there is a H1 or HL, does this mean anything? On the intake it says GM 1, does this mean anything? I have seen some that have GM and another number. There is some other letters on the rear of the heads ML-R is what it looks like.
Mean anything??

Thanks
Eldon

Congrats!

GM1 is the foundry in which your heads were cast. 4X 1H are 114 cc, large intake, small exhaust heads.

4X-1H uses 4.881/4.870" tall valves
4X-1H are 455 head with 114cc, 2.11/1.66" valves and pressed studs.

You really don't need "all kinds of performance parts". Honest. If you just want an enjoyable street driver, heads that will yield a pump gas friendly but higher compression ratio, plus a more appropriate cam to help them out, will make a nice streetable non-finicky car. Just rebuild with quality stock components and it'll be fun.

Of course, if you do order all kinds of performance parts, you can have more fun. But eventually all that power exceeds traction and is wasted until you re-engineer the chassis. Then the vicious cycle begins.

I think you should put a blower on it!!!!!LOL I know, everyone loves a smart axx.

I have a low miles 73 455 with 6X 8 heads all stock other than bolt ons in my 67 with a 2.56 rear posi and a TH400. Not the best combination for off the line performance, but in stock form it can still light em up off the line with very little effort! If you get on it it will get slideways in an instant.

Yes, I plan on doing more with it and changing the gearing slightly at some point... but just goes to show you what kind of torque the stock low compression 455 has in a lighter car like the 1st gen.

So as Vikki & others stated, you can get a LOT out of it with out doing much to it at all. You'll still have room to grow if the erge should strike you...

Brett - 67 Drop Top 455!

Aluminum heads would be the ticket if you have them in your budget.

Why?

Oh, many reasons.... One being you can burn pump gas with higher compression using aluminum heads.

No need. He needs to increase compression from 8:1 to 9.5:1. There is no need to go to 10:1 or beyond. The 455 in stock trim with 455 factory non-econo heads will suit his stated intentions.

I just don't see the point in recommending something that will not help someone reach their stated goals. In this case, cruiser/driver. Even the 4X heads may suffice, but if the heads need to be rebuilt, better to start with a more suitable casting.

Oh yes, aluminum heads will help very much for his car to become a good cruiser and driver. The advantages are obvious. With today's poor quality gas you would have to be an ostrich not to see the benefits. Or just plain argumentative! They are not a must. But they will help achieve just about any goals you have with your first gen. They are a great option not to be taken off the table in any build. Unless, of course, you are trying to stay exactly original.

I have spent the morning talking to the people that will most likely be doing my machine work here. We have a great speed shop that takes care of the racing group and also we have Scoggin- Dickey here in town that is nationaly know. One of the ideas that they talked about would be domed pistons to raise the compression some and clean up the heads for better flow and a better cam.
Sound good to me but I need to hear from the people out there that have had experience with Pontiacs and will the domed pistons create more trouble than it's worth?

Thanks
Eldon

P.S. My budget would allow for alum. heads but that seems over the top ( a little) for the way I will use this car.
I have a 68 Z28 that gives me that thrill. This car will be for my wife and me to go to the Sonic for a shake. You know, stuff like that.

Rule number 1 is always listen to your builder.
Rule number 2 is that Chevy engine builders sometimes don't have a clue with Pontiacs.
The domed pistons are a Chevy thing. Flat top pistons(original to Pont.) give you better heat distribution on the face of the piston.
Aluminum heads would get you exactly where you want to go with the original style pistons. They also keep your engine cooler. There are also some nice iron heads out there. You will just have to be a little more careful with your fuel choice with them. Which brings up the question; What kind of fuel do you plan on burning?

Scroggin-Dickey...are they related to Scroggins machine shop in Houston?? if so they will know Pontiacs too....

Adding domed pistons and doing a lot of machining to improve the flow and compression of emissions heads is the long road to making improvements. Why spend money on shop work that would be better spent on better cores to build?

Just get a set of heads that will deliver your desired compression ratio for your intended fuel and use, and match the cam to the combo.

Thats what I will do. The domed piston thing did kinda worry me.
Thanks.

Eldon

No, I don,t think Scoggin-Dickey has anything to do with the Houston shop.