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BB 454 for 1980-82, will this Fit?

Rebelrob

Well-known member
Joined
Apr 9, 2009
Messages
94
Location
Dallas, TX
Corvette
1982 Collectors Edition
Hello, I just joined this group. I have inherited an original LS7 454 Crate Motor. I think it was purchased in the early 70's. Its sitting on an engine stand. I plan to take it to a local engine builder and have it rebuilt and made bullet proof to run on 93 octane pump gas since its specs are 12.25:1 Compression. Just want to know if this will fit into a 80-82 model vette. I really like these specific models and I also like the price. I plan to purchase one so I can have a home for this LS7. I also have a Turbo 400 trans and torque converter, posi-track differential sitting next to it. I prefer a 4 speed, but figured since I already have the T400 I would stick with this.
I also plan to put side pipes on it. Very excited about, considering I dont even have the car yet...
Thanks for any feedback.....
R
 

KANE

Moderator
Joined
Mar 2, 2002
Messages
3,243
Location
KY
Corvette
Dark Blue 1982 Trans Am(s): Polo Green 1995 MN6
Hello, I just joined this group. I have inherited an original LS7 454 Crate Motor. I think it was purchased in the early 70's. Its sitting on an engine stand. I plan to take it to a local engine builder and have it rebuilt and made bullet proof to run on 93 octane pump gas since its specs are 12.25:1 Compression. Just want to know if this will fit into a 80-82 model vette. I really like these specific models and I also like the price. I plan to purchase one so I can have a home for this LS7. I also have a Turbo 400 trans and torque converter, posi-track differential sitting next to it. I prefer a 4 speed, but figured since I already have the T400 I would stick with this.
I also plan to put side pipes on it. Very excited about, considering I dont even have the car yet...
Thanks for any feedback.....
R

That engine will fit... you'll want to pay attention to the height of your intake manifold though. Some intake manifolds are higher than the OEM dual plane that came on BBC Vettes. A tunnel ram or high rise intake will require cutting the hood or getting a new hood.

The 82 Vette's hood has a fresh air door underneath and that will bump an air filter sitting on top of a big block.

Hope that helps.
 

73shark

Well-known member
Joined
Jun 24, 2007
Messages
603
Location
KC, MO area
Corvette
1973 Orange Metallic L-82 Coupe
:welcome

With all of that LS-7 torque, you'll quickly find the weak link(s) in the drive train if you intend to flog it. Also be prepared to spend prodigious amounts of cash for all of the items needed to adapt the BBC to a Shark.

Do you plan on factory sidepipes or something like the Hooker "nest of snakes"? The reason I mention this is because the OEM Corvette BBC cast iron manifolds are pricey.

Good luck and keep us posted on the progress. Lots of pics. :beer
 

Hib Halverson

Technical Writer for Internet & Print Media
Joined
Jan 10, 2001
Messages
13,452
Location
CenCoast CA
Corvette
71 04 12 19
You have to decide what the term "fit" means.

yeah, the engine will bolt in place but no stock hood will clear it. You'll have to go aftermarket for a hood.

You already know the engine's compression ratio is too high. To run detonation free on 93 octane gas, an aluminum head big-block needs to be down around 10.0:1. Also I think you're going to find that the 60s-style cam profile used in the LS7 isn't going to work real well with the lower compression.

An LS7 is not going to work very well with an automatic unless you've got a high-stall converter and short gears. Also, a stock TH400 is not going to be very durable behind an engine like that so figure on additional mods to make the trans live.

In short, LS7 into 80-82 can be made to work but you're looking at something that's a little more complex than just bolting in the LS7.
 

Rebelrob

Well-known member
Joined
Apr 9, 2009
Messages
94
Location
Dallas, TX
Corvette
1982 Collectors Edition
Thanks for the input thus far.

Nothings ever easy is it....
Yeah, My dad had a after market hood on his 73 when he had it installed at the time. You could barely see over the tall cowl...
He turned that into a Pro street version. Little too radical for me.

Well the TH400 is not stock. It was built to work with the LS7.
When you mentioned drive train did you mean the Trans or the rear end itself? I would probably need to have that rebuilt as well.
Im not interested in AC, just want the essentials. Hopefully a mechanical fan with some electrics on the front of the radiator. I have read that maybe the suspension will need to be upgraded up front as well. I guess I will have to piece it all together. I would like side pipes coming out of normal headers. I just do not know much about them. As for the engine itself. It has the original cast iron retangular port heads. I do not want aluminum with the fear them cracking/warping if it gets to hot. I am just hoping to keep the same power with having the heads redone, valves, etc..
Thanks again,
R
 

GO_VETTE

Well-known member
Joined
Feb 6, 2009
Messages
230
Location
Queens, NY
Corvette
1984 Pearl White Coupe
Hello, I just joined this group. I have inherited an original LS7 454 Crate Motor. I think it was purchased in the early 70's. Its sitting on an engine stand. I plan to take it to a local engine builder and have it rebuilt and made bullet proof to run on 93 octane pump gas since its specs are 12.25:1 Compression. Just want to know if this will fit into a 80-82 model vette. I really like these specific models and I also like the price. I plan to purchase one so I can have a home for this LS7. I also have a Turbo 400 trans and torque converter, posi-track differential sitting next to it. I prefer a 4 speed, but figured since I already have the T400 I would stick with this.
I also plan to put side pipes on it. Very excited about, considering I dont even have the car yet...
Thanks for any feedback.....
R



:):);LOL
HOLY Shiiiiiip!
i am excited to see that 454 motor in a tiny Vette.
 

minifridge1138

Well-known member
Joined
Feb 2, 2007
Messages
908
Location
USA
Corvette
1982 Black Fastback
Yes it will fit without modification (other than the hood, most likely).

I am jealous and can't wait for pictures / video.
 

Ed's 1970

Well-known member
Joined
Sep 17, 2006
Messages
87
Location
SoCal
Corvette
1970 Stingray coupe
Compression is way too high, especially with those very heavy iron heads u will need race gas:eek:hnoes Your going to have to get that compression down somehow...pistons, heads, head gaskets. Yep, I was going to go with stock LS6 heads on my 540 build but changed my mind. I ended up getting some aluminum merlin 3's. Half the weight, better flow, and great looking!
U can run about a point higher compression with alum heads. The exhaust ports are in the stock location too, so all the brackets fit and the headers fit like on stock heads. They are similar to Brodix Race Rite heads, but the chambers are bigger at 320 CC's, most likely too big for your 454. The brodix head would be just about perfect for your engine with the intake at 269 cc's or u may be able to find a head with a bigger chamber to lower your compression. I wouldn't worry about a new aluminum head warping. My small block LT1 makes about 600 horse and it had aluminum heads from the factory. I run the shit out of that motor for 15 years now, only thing I broke were the pistons 'cause I ran too much boost.

Also u may want to change out the camshaft to a roller.

U do realize that because the car is a 1980, this swap may be illegal in some states including my own CA and in NJ. It would have a very hard time passing smog, don't u think? This is why I purchased a 1970 Vette.
 

Rebelrob

Well-known member
Joined
Apr 9, 2009
Messages
94
Location
Dallas, TX
Corvette
1982 Collectors Edition
Yep, Im hearing a lot about reducing the compression. Dang, how can I keep all that power the engine came with? I am not that knowledgeable about how this all works. I want a nice fat cam and lots of torque. I plan on rebuilding the 700r4 trans. I am not looking to drag race or anything, just for cruising. I like that 4th gear overdrive.
Actually its an 82 and in Texas if its over 25 years, they only do a safety inspection. They dont care about emissions, exhaust and all that other horse Sh*t. So Im good there.
Thx for the info about the heads.

R


Compression is way too high, especially with those very heavy iron heads u will need race gas:eek:hnoes Your going to have to get that compression down somehow...pistons, heads, head gaskets. Yep, I was going to go with stock LS6 heads on my 540 build but changed my mind. I ended up getting some aluminum merlin 3's. Half the weight, better flow, and great looking!
U can run about a point higher compression with alum heads. The exhaust ports are in the stock location too, so all the brackets fit and the headers fit like on stock heads. They are similar to Brodix Race Rite heads, but the chambers are bigger at 320 CC's, most likely too big for your 454. The brodix head would be just about perfect for your engine with the intake at 269 cc's or u may be able to find a head with a bigger chamber to lower your compression. I wouldn't worry about a new aluminum head warping. My small block LT1 makes about 600 horse and it had aluminum heads from the factory. I run the shit out of that motor for 15 years now, only thing I broke were the pistons 'cause I ran too much boost.

Also u may want to change out the camshaft to a roller.

U do realize that because the car is a 1980, this swap may be illegal in some states including my own CA and in NJ. It would have a very hard time passing smog, don't u think? This is why I purchased a 1970 Vette.
 

Ed's 1970

Well-known member
Joined
Sep 17, 2006
Messages
87
Location
SoCal
Corvette
1970 Stingray coupe
Today's big block heads flow a lot better than the heads from the 60's. That is why u can still make big power without having higher compression.
With good heads, the camshaft becomes more important. One thing u have to watch out for with a higher lift camshaft is piston to valve clearance, especially with higher dome pistons which I think u have. With the iron heads your compression should be around 9:1. With aluminum up to around 10.5:1. On the LS7 I don't know if they went with small cc closed chambers on the heads or domed pistons to get that 12:1 ratio. Chevy high performance has run motors with close to 11:1 still on pump gas with alum heads(they claim). Don't worry, your motor will still be plenty stout, its a big block with big torque. With a 454, 550 horse should be easy to make with good driveability. With an auto it gets a little tricky with the camshaft selection and stall converter, you probably want to stick with a mild hydraulic roller. I'm putting in a richmond 6 speed in my car so I don't have to worry about that, I have a street solid roller I may try out first, but don't want too radical of an idle.
 

Rebelrob

Well-known member
Joined
Apr 9, 2009
Messages
94
Location
Dallas, TX
Corvette
1982 Collectors Edition
I see. Rectangular port heads. That's all know about them. They are big and they are heavy. Let me tell ya.

Wonder how much a nice set of aluminum heads for that would run me?

As for the cam, I just love that wicked idel sound that a good cam produces. Its music to my ears....
One thing I am concerned about is there is some half cross member under the car. And the stock exhaust and cat bend around the side of it. Im hoping a custom exhaust shop can make some special bends and run dual exhaust around the same area... hmmmm.
Does not have the two big holes in the cross member like I have seen on the older 70's vettes.


Today's big block heads flow a lot better than the heads from the 60's. That is why u can still make big power without having higher compression.
With good heads, the camshaft becomes more important. One thing u have to watch out for with a higher lift camshaft is piston to valve clearance, especially with higher dome pistons which I think u have. With the iron heads your compression should be around 9:1. With aluminum up to around 10.5:1. On the LS7 I don't know if they went with small cc closed chambers on the heads or domed pistons to get that 12:1 ratio. Chevy high performance has run motors with close to 11:1 still on pump gas with alum heads(they claim). Don't worry, your motor will still be plenty stout, its a big block with big torque. With a 454, 550 horse should be easy to make with good driveability. With an auto it gets a little tricky with the camshaft selection and stall converter, you probably want to stick with a mild hydraulic roller. I'm putting in a richmond 6 speed in my car so I don't have to worry about that, I have a street solid roller I may try out first, but don't want too radical of an idle.
 

73shark

Well-known member
Joined
Jun 24, 2007
Messages
603
Location
KC, MO area
Corvette
1973 Orange Metallic L-82 Coupe
You could probably get an early crossmember for an auto tran. frame which was a bolt-in and put it in yours.

I'm pretty sure the LS-7 heads were open chamber.
 

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