Big Block upgrade
Thread Starter
3rd Gear
Joined: Jul 2013
Posts: 3
Likes: 0
Big Block upgrade
I have a 1976 corvette that I am going to put in a 1991 454 built engine in any suggestion? I know the obvious motor mounts, hood, front springs, sway bars bigger brakes but does anyone know something else? Has anyone done this upgrade? I also have a 4l80e trans in the donor truck the motor is out of. Any thought on using this? Thanks for your input new to this forum!!
Instructor
Joined: Jul 2013
Posts: 104
Likes: 15
From: Bennington VT
I would also recommend upgrading the cooling system to include the radiator and high flow water pump. I installed a Griffin aluminum radiator and Edelbrock Victor water pump on my 70 454 coupe and my operating temperature always stays around 180 degrees. You should also look at the exhaust system as well. A 350 has 2 inch exhaust pipes and the 454 has 2 1/2 pipes.
Le Mans Master
Joined: Jan 2006
Posts: 6,505
Likes: 139
From: Butler Pa
I have a 1976 corvette that I am going to put in a 1991 454 built engine in any suggestion? I know the obvious motor mounts, hood, front springs, sway bars bigger brakes but does anyone know something else? Has anyone done this upgrade? I also have a 4l80e trans in the donor truck the motor is out of. Any thought on using this? Thanks for your input new to this forum!!
Le Mans Master
Joined: Jan 2006
Posts: 6,505
Likes: 139
From: Butler Pa
I would also recommend upgrading the cooling system to include the radiator and high flow water pump. I installed a Griffin aluminum radiator and Edelbrock Victor water pump on my 70 454 coupe and my operating temperature always stays around 180 degrees. You should also look at the exhaust system as well. A 350 has 2 inch exhaust pipes and the 454 has 2 1/2 pipes.
Drifting
Joined: Jan 2011
Posts: 1,853
Likes: 81
From: Hamilton Virginia
What do you mean " built " ? If you plan on having alot of horses and racing it around, you will need something stronger than the th350 thats in it. you will also have to change out the rear shafts to bigblock. If its an early 76 then the radiator that is in it is good if its in great shape and all the seals are good. Change out the front springs to big block. Might need a taller hood depending on your intake. Exhaust either needs to change to 21/2 or add bigblock headers and sidepipes. The oil pan that is on the 1991 motor might not work with the P/S system if it has p/s. The 1991 is throttle body system, so if your staying with it, fuel pump and wiring upgrades are needed. Then there is a question of the accessory system and what your going with.
Le Mans Master
Joined: Apr 2007
Posts: 7,353
Likes: 72
From: Graceland in a Not Correctly Restored Stingray
What does "built" mean? As much of a big block fan as I may be, the stock 454 that came in my former '91 dually isn't something I can imagine putting into a Corvette without bumping up the CR and swapping in a decent cam that's not done by ~4000. My $.02
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Burning Brakes
Joined: Jun 2010
Posts: 1,165
Likes: 93
From: Bellmore NY
With that said, its also a GEN V motor, which means no fuel pump boss. Not that running an electric pump is a big deal, but it is mandatory in this case.
Do some research on GEN V motors and fitment before you buy any parts.
Burning Brakes
Joined: Feb 2012
Posts: 925
Likes: 7
If running factory cast iron manifolds, note that there may be a difference between Corvette Big Block manifolds and the ones on the donor truck. A Corvette cast iron manifold is different than say on a Chevelle/Camaro.
Team Owner
Joined: Jul 2004
Posts: 40,368
Likes: 787
From: Redondo Beach, California
Does this 1991 454 have the "peanut" heads? These cylinder heads had restricted intake runners, even more restricted that the early C3 BB's. They're called peanut heads, because if you look at the intake of the heads they have what looks like little peanuts cast into the heads.
I know that the Big Blocks, as originally sold, were usually all cast iron. My 1970 came stock with a all cast iron engine, even a cast iron intake manifold. JUST REALLY GROSS! An they had cast iron exhaust manifolds.
The potential power of a BB is somewhat negated by all this cast iron. Not to say about all the front wheel weight bias. However, my all cast iron BB 1970 nevertheless gave exhilarating performance when I was driving it.
Don't know what your budget is. I'd suggest buying after market aluminum heads and intake manifolds if you can swing it. This gets the weight down to close to Small Block weights.
Also, does your 1991 454 have the peanut heads? You can buy used oval port iron heads pretty cheaply.
Best of luck with your project, your car really needs a lot of more HP to match its potential and looks. Putting a BB in shouldn't create big fitment issues. Have you considered a stock BB hood?
I know that the Big Blocks, as originally sold, were usually all cast iron. My 1970 came stock with a all cast iron engine, even a cast iron intake manifold. JUST REALLY GROSS! An they had cast iron exhaust manifolds.
The potential power of a BB is somewhat negated by all this cast iron. Not to say about all the front wheel weight bias. However, my all cast iron BB 1970 nevertheless gave exhilarating performance when I was driving it.
Don't know what your budget is. I'd suggest buying after market aluminum heads and intake manifolds if you can swing it. This gets the weight down to close to Small Block weights.
Also, does your 1991 454 have the peanut heads? You can buy used oval port iron heads pretty cheaply.
Best of luck with your project, your car really needs a lot of more HP to match its potential and looks. Putting a BB in shouldn't create big fitment issues. Have you considered a stock BB hood?
Drifting
Joined: Aug 2004
Posts: 1,883
Likes: 124
From: Lubbock TX
Also keep in mind that the Gen 5 has some head gasket issues when used with some aftermarket and pretty much all earlier GM heads...may or may not be able to bolt aftermarket heads to it, it's a crap shoot at best.
Burning Brakes
Joined: Jun 2009
Posts: 840
Likes: 4
From: Syracuse IN
Go for it, I transplanted a 375hp Gen V 454 into our old motorhome several years ago. I utilized the GM MPI intake and a MEFI 3 controller. Once I did that, we could pull 9k lbs easily 70 to 75 mph. Oh, the motorhome itself weighed 16Klbs. Miss, that ole dog! The Gen V has multiple applications and many, many aftermarket upgrades. Butt loads of torque also. Al
Le Mans Master
Joined: Dec 2003
Posts: 5,381
Likes: 415
From: N J
Go for it, I transplanted a 375hp Gen V 454 into our old motorhome several years ago. I utilized the GM MPI intake and a MEFI 3 controller. Once I did that, we could pull 9k lbs easily 70 to 75 mph. Oh, the motorhome itself weighed 16Klbs. Miss, that ole dog! The Gen V has multiple applications and many, many aftermarket upgrades. Butt loads of torque also. Al
Here's my 454 in my 77. I didnt want to change the stock look of the car so my hood stayed.
Thread Starter
3rd Gear
Joined: Jul 2013
Posts: 3
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I had the engine punched out 60 heads reworked hi pro cam msd ignition etc less than 10000 miles on rebuild. It was a strong motor lots of torque and pretty fast considering it was in a 1 ton dually. I think I will go with carb instead of throttle body save the expense of reworking the computer.
Burning Brakes
Joined: Jun 2009
Posts: 840
Likes: 4
From: Syracuse IN
I wished I still had that ole Motorhome, at least the engine and drivetrain. Sold to a guy who goes to local redneck car racing. It would be an easy install into a Vette due to the nearly flat top intake assy. Heck if a GM 8100, ie 496 MPI will fit in a Vette a 454 vortec surley will. Al
Melting Slicks
Joined: Jul 2009
Posts: 2,091
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Burning Brakes
Joined: Sep 2011
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The 4L80e is a great transmission for performance. If it needs a rebuild, check out Jakes Performance Transmissions. The transmission tunnel may have to be trimmed a bit. I havnt done this swap but am thinking about it. Good Luck!
Le Mans Master
Joined: Dec 2003
Posts: 5,381
Likes: 415
From: N J
Edelbrock performer RPM intake. Holley 750 double pumper carb with a stock drop base vette aircleaner and a flat cap for it. Has about an inch of room left under the stock 77 hood. Sadly I cant remember which ports. grrrr