Lt1 Aluminum heads...can I use them in a Gen 1 SBC Build?

Hey all,

I ran across a reasonably priced (I think...probably) set of aluminum LT1 heads on the local craigslist. So I wanted to ask here about if it would be worth incorporating them into a SBC build. I have a couple of flat tappet 350 core blocks sitting around I'd like to rebuild eventually.

Keep in mind...I don't even know what I'm building this engine for yet...but most likely it would be a G-body Malibu or Regal that I would like to use for weekend fun, twisty roads, and the outside chance of a track day in the future (outside chance). Primarily a street car for pure driving pleasure (Think...drive to work on perfect days and to the cruise night once a month, and on the weekends to go drive for fun).

Anyway...I know that to use these with a carb, I'll need an expensive special manifold. I figure one of those can be had used off a forum for not too much, hopefully.

What other bolt-it-up-and-go issues will there be? Cooling system? Will these work with a regular SBC water pump, or do I need to use an LT1 pump? Or what else can be done?

Would it be worth it? I know I've heard the aluminum LT1 heads didn't flow as well as the iron LT1 heads...but do they still flow pretty well? Because, honestly, otherwise, I'd probably just rebuild a set of smog heads for this build. These aluminum ones I've found would be significantly less than a new pair of vortec iron heads, for comparison.

I just thought I'd see what the folks with experience here thought about this.

Thanks! Clem

From der Googles http://www.thirdgen.org/techboard/tpi/178262-completed-lt1-heads-gen1.html

Thanks John. I'm generally leery of 9 year old thirdgen.org threads. I'll check it out.

Was hoping for some BTDT experience from folks here...

Thanks again, Clem

Car Craft might have an article on the subject. If its possible, they'll definitely have an article on the subject. Chances are it will be a few years back, the LT1 isn't the new hot setup anymore for some reason.

The long answer is yes, the short answer is an emphatic NO.

They will physically bolt up, but the water passages don't line up. You would have to weld, drill, resurface, etc. Then you would have welded, machined factory heads that only flow slightly better than TPI heads.

Iron LT1 heads flowed better than the aluminums anyway, and the port in the LT1 was copied down to the millimeter for 96-99 Vortec heads (castings 062 and 906).

What I'm saying is, you can get better performance with a bolt-on Vortec head than you can from the thousands you'd spend on modifying aluminum LT1s

I'll write more later but i'm late for lunch. Classic iron is my bag, baby.

you could do it- and it has been done- but why?

LT1 head gasket and intake gaskets:

gen 1 (non LT1) head gasket and intake gaskets:

you can see that there are a few differences..

It has little to do with the direction of the flow. Many times people get confused by "reverse flow heads" thinking that its something special about them that they can't be used. People just refer to them as "reverse flow" because they came from an engine with reverse flow coolant.

The biggest hurdle will be the water passages - welding, drilling, surfacing, and then you're left with welded cast aluminum (which is never good) with thin factory decks and only about 20% more flow than stock smoggers.

Like I said before, the best flowing factory head port was the LT1 iron which is the same as the Vortecs. Vortecs are a bolt-on with the correct intake. The LT1 wasn't anything special. Rotating assemblies are the same old SBC1 stuff. As far as volumetrically speaking, LT1 = SBC.

There are several aftermarket Vortec heads that cure the huge internet myth of cracking decks. They're cheap. Way cheaper than modifying LT1 heads to fit.

curtis73 wrote: I'll write more later but i'm late for lunch. Classic iron is my bag, baby.

dang I feel old. I never thought of the LT-1 as "classic" but I suppose it is 20 yrs old now

a401cj wrote:

curtis73 wrote: I'll write more later but i'm late for lunch. Classic iron is my bag, baby.

dang I feel old. I never thought of the LT-1 as "classic" but I suppose it is 20 yrs old now

well, it was the most high tech version of an engine family that came out in the fall of 1954..

novaderrik wrote: well, it was the most high tech version of an engine family that came out in the fall of 1954..

Jokes

The man has them

curtis73 wrote: It has little to do with the direction of the flow. Many times people get confused by "reverse flow heads" thinking that its something special about them that they can't be used. People just refer to them as "reverse flow" because they came from an engine with reverse flow coolant. The biggest hurdle will be the water passages - welding, drilling, surfacing, and then you're left with welded cast aluminum (which is never good) with thin factory decks and only about 20% more flow than stock smoggers. Like I said before, the best flowing factory head port was the LT1 iron which is the same as the Vortecs. Vortecs are a bolt-on with the correct intake. The LT1 wasn't anything special. Rotating assemblies are the same old SBC1 stuff. As far as volumetrically speaking, LT1 = SBC. There are several aftermarket Vortec heads that cure the huge internet myth of cracking decks. They're cheap. Way cheaper than modifying LT1 heads to fit.

actually, the vortec heads are a lot different than the iron LT1 heads.. the vortecs were based on the iron LT1 heads, but they are better in every way.

vortec intake ports are taller than the LT1 heads and the vortec combustion chambers have more of a heart shape to them with more of a quench area than the LT1 heads. the exhaust ports look about the same, tho.

the iron LT1 heads are better than the aluminum LT1 heads, but you can just tell by looking at them that the vortecs are best heads of the bunch.

Is there any reason to use any of them with the price of 5.3L gen iii+ motors?

Taiden wrote: Is there any reason to use any of them with the price of 5.3L gen iii+ motors?

nostalgia.. it's the same reason people still build flathead powered hot rods and wear their 50's greaser costume when they drive it..

novaderrik wrote: actually, the vortec heads are a lot different than the iron LT1 heads.. the vortecs were based on the iron LT1 heads, but they are better in every way.

I agree.... I only said they copied the ports.

The ports on Vortecs are taller, but not by much. They ease the transition from the large intake ports down to the throat.

novaderrik wrote:

a401cj wrote:

curtis73 wrote: I'll write more later but i'm late for lunch. Classic iron is my bag, baby.

dang I feel old. I never thought of the LT-1 as "classic" but I suppose it is 20 yrs old now

well, it was the most high tech version of an engine family that came out in the fall of 1954..

I'm 38, but I should have been born in 1948. That would have made me the perfect age to be a hippie with a 67 GTO. :)

I meant "classic iron" as traditional SBC, not the LT1. I'm still trying to wrap my mind around why Car Craft and Hot Rod keep talking about an LS7 and then not showing a picture of a BBC :)

curtis73 wrote:

novaderrik wrote: actually, the vortec heads are a lot different than the iron LT1 heads.. the vortecs were based on the iron LT1 heads, but they are better in every way.

I agree.... I only said they copied the ports. The ports on Vortecs are taller, but not by much. They ease the transition from the large intake ports down to the throat.

for some strange reason, i've still got the intake gaskets from my Caprice LT1 and the first set of intake gaskets i used on the vortec headed 355 i had in my Nova, and the vortec ports are at least 1/4" taller than the LT1 ports. the LT4 heads were probably closer to the Vortecs than the iron LT1 heads were, and you can get a gen1 version of those heads if you get a set of Fastburns..

but even those heads are 15 year old techonology, and you can get a newer 5.3 in a car and running for about the cost of a set of vortec heads and the matching unique parts to use them..

novaderrik wrote: but even those heads are 15 year old techonology, and you can get a newer 5.3 in a car and running for about the cost of a set of vortec heads and the matching unique parts to use them..

Major agree.

I did find some actual pricing for the OP.

You can buy brand new assembled GMPP Vortec heads from Summit for $300 each

You can buy used Vortec heads for $200 a pair all day every day from CL

You can buy aftermarket Vortec heads with thicker decks for $575 a pair. Cheaper than new GM vortecs with much thicker decks.

If you really want aluminum, you can buy Brodix, Dart, Edelbrock, or Trick Flow heads starting at around $375-400 each.

.... no point modifying LT1s in my opinion.

a401cj wrote: dang I feel old. I never thought of the LT-1 as "classic" but I suppose it is 20 yrs old now

The LT-1 is 41 years old.

The LT1 is 20 years old.

A hyphen makes a world of difference

Doing the LT1 head swap looks about as involved as swapping Cleveland heads onto a Windsor block, which has the same problem - the coolant return (well, inlet in the Chevy) is in the deck and not the manifold face. A lot of the Cleveland heads would just get the deck hole drilled out round and get a core plug rammed in place. Why wouldn't this work for the Chevy?

Or, hell, JB Weld it, sand it flat, smear of silicone on it for good measure. I've gotten away with worse.

Anyway, here's an enlightening and sometimes humorous account of finding the differences between an LT1 and a small-block, the fun way: http://www.bacomatic.org/~dw/engine/lt1/lt1.htm

Best quote: "Remember, Chevy stuff all interchanges, and they're easy to work on... "

Taiden wrote: Is there any reason to use any of them with the price of 5.3L gen iii+ motors?

Hot Rod did a cam swap story in the latest issue.

The cam was something like $400, but it needed different valvesprings because the OE springs suck, which were... more than the cam. Total parts for the cam swap was over $1000.

How's that for a reason?

Roller cams are expensive. They don't make flat-tappet cams for the new engines. And, on the street, radical cams eat the needles on roller lifters, even if you keep up on your valve adjustments.

Perverse, yeah?

Knurled wrote:

a401cj wrote: dang I feel old. I never thought of the LT-1 as "classic" but I suppose it is 20 yrs old now

The LT-1 is 41 years old. The LT1 is 20 years old. A hyphen makes a world of difference Doing the LT1 head swap looks about as involved as swapping Cleveland heads onto a Windsor block, which has the same problem - the coolant return (well, inlet in the Chevy) is in the deck and not the manifold face. A lot of the Cleveland heads would just get the deck hole drilled out round and get a core plug rammed in place. Why wouldn't this work for the Chevy? Or, hell, JB Weld it, sand it flat, smear of silicone on it for good measure. I've gotten away with worse. Anyway, here's an enlightening and sometimes humorous account of finding the differences between an LT1 and a small-block, the fun way: http://www.bacomatic.org/~dw/engine/lt1/lt1.htm Best quote: "Remember, Chevy stuff all interchanges, and they're easy to work on... "

i do respect what that guy did to put all the gen 1 stuff on the LT1, but it would have been so much easier to just get an LT1 carb intake manifold, keep the cam driven water pump, and use readily available and cheap B body (Caprice, Roadsmasher, etc) front accessories.

novaderrik wrote:

Taiden wrote: Is there any reason to use any of them with the price of 5.3L gen iii+ motors?

nostalgia.. it's the same reason people still build flathead powered hot rods and wear their 50's greaser costume when they drive it..

A lot of people still like the older motors (nostalgia or other reasons) and while the costs of swapping LS engines has come down, they are still a bit more expensive than the old engines, especially if you have all the accessories for an old sbc engine (mounts, headers, alternator, etc). Unless of course you start with a car with no engine, then it is pretty close.

I still prefer the torque curve of the older engine, it tended to be stronger in the low to mid range. Mid to high the LS engines are better. Not that you can't get an older small block to spin up higher, my 377 loves to turn up and is a blast.

novaderrik wrote: but even those heads are 15 year old techonology, and you can get a newer 5.3 in a car and running for about the cost of a set of vortec heads and the matching unique parts to use them..

I'm going to call a tentative "BS" on this statement. Can you honestly tell me that one can get a 5.3 and the unique parts to use it for "about the cost of" a pair of vortec heads and a special intake?

'Cause I don't think you can. I am more than willing to find out how it works though...because I'll do it if so. (I'm not talking all new parts here...in case that's not apparent.)

To that end...if I wanted to put an "LS" type engine in my '82 chevy 4x4, I'm guessing I would need: Engine, carb manifold ($$$ I bet) or fuel injection stuff, accessory brackets, flywheel, engine mounts (are they different than Gen 1?), some way to run the spark...I have no idea about that but I smell dollar signs.

Again, I'm genuinely open to input/example. Because I'd LOVE to know how to get an LS type engine in a project for $500-$1000.

I'm not arguing that LS stuff is super expensive...It's very attractive to me...but the LS revolution has made Gen 1 stuff STUPID cheap (used).

For the record...this thread has cured me of the curiousity about if I should pick up a set of LT1 heads...being as I don't have an LT1 to put them with. The guy priced them at $250 but asked what my offer was. So...if someone has an LT1 and needs some heads, I can put you in touch.

Thanks for the discussion, folks!
Clem

For the LS swap: -New carb manifold: $300 (don't buy the kit with the spark box) -MSD spark box: $300 (saves you $100 over the E-brock kit, and programmable) -Motor mount brackets, if you cant drill 5 holes in a piece of 1/4" plate: $40 -Flywheel for MT: $60 at autozone, use your existing clutch or -Adapter for AT: $45, use a file to elongate holes in 5.3L flexplate -5.3L engine, with all accessories, starter, truck manifolds, and flexplate: $500 all day long, usually cheaper, and the 285hp 4.8 is even cheaper still.

Total:$1200 tops. Plus the same carb and exhaust work you would need with any other swap. Given that the last three 5.3s I bough were under $200 each, under a grand should be very easy to achieve, even buying the manifold and MSD box brand new.

oldopelguy wrote: -5.3L engine, with all accessories, starter, truck manifolds, and flexplate: $500 all day long, usually cheaper, and the 285hp 4.8 is even cheaper still.

I found that the 4.8 is more expensive than the 5.3. I can find 5.3s for as cheap as $700-800 but 4.8s are all over $1000.

Less common and all that. IIRC the 4.8 only came in RWD.

Really? Must be a local thing, but there are some yards out there are on the crackpipe on prices for a 4.8 . . .