Blown BBC Swap final answers and opinions
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Car: '91 Firebird
Engine: 468 BBC w/ 8-71 blower
Transmission: Th400
Axle/Gears: 9-bolt 2.77
Blown BBC Swap final answers and opinions
Ok, I've got a blown 468 with an 8-71 blower, pushing around 980hp under driven 14% running on pump gas. It will be Going into a '91 t-top Firebird originally a v6 car. I will be adding an 8 point roll bar set up along with weld in subframe connectors to stiffen up the unibody. I've seen guys run similar engines in t-top cars without that but I'd rather have the extra rigidity. My current plan is to swap it in with the current 700r4 and 9-bolt 2.77 rearend. Not running slicks, just street tires, not going to see the track until money for a beefier drivetrain becomes available and even then it's only gonna hit the track maybe once a year for a test and tune. My goal is to have a fun, ridiculous street and show car. Anyway enough background and setup, onto my questions. Cooling: Will a V8 Radiator from a fourth gen with twin fans be enough? Should I run a thermostat?
Drivetrain: Will the stock setup live with street tires and no hard launching for a couple of years? Obviously I will monitor the trans temp via a temp gauge. I also plan on running an aftermarket trans cooler.
Exhaust: The common swap headers I've seen are 1 7/8" primaries, I'd much rather run 2"+ does anyone know where I can find such s thing with paying 1200+ for custom headers? And am I better off going out in front of the front tire as I've seen a few guys do? Or better to go all the way back or somewhere in between. (Cops in my neighborhood aren't too strict on loud exhaust as long as you're not constantly revving it up to **** people off)
Any other suggestions or things I'm over looking? Thanks!
Drivetrain: Will the stock setup live with street tires and no hard launching for a couple of years? Obviously I will monitor the trans temp via a temp gauge. I also plan on running an aftermarket trans cooler.
Exhaust: The common swap headers I've seen are 1 7/8" primaries, I'd much rather run 2"+ does anyone know where I can find such s thing with paying 1200+ for custom headers? And am I better off going out in front of the front tire as I've seen a few guys do? Or better to go all the way back or somewhere in between. (Cops in my neighborhood aren't too strict on loud exhaust as long as you're not constantly revving it up to **** people off)
Any other suggestions or things I'm over looking? Thanks!
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Car: '91 Firebird
Engine: 468 BBC w/ 8-71 blower
Transmission: Th400
Axle/Gears: 9-bolt 2.77
Re: Blown BBC Swap final answers and opinions
Also! Suspension: I've read something about guys using V6 front springs for BBC swaps? Why? And anyone have suggestions on a decent brand that doesn't cost an arm and a leg?
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Car: 1990 Formula Firebird
Engine: 305 TBI (LO3)
Transmission: WC T-5 out of an 88 T/A
Axle/Gears: 10 bolt, 3.42 & Torsen Posi
Re: Blown BBC Swap final answers and opinions
When you say the current 700R4 do you mean the one from the car or one currently on the motor?
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Car: '91 Firebird
Engine: 468 BBC w/ 8-71 blower
Transmission: Th400
Axle/Gears: 9-bolt 2.77
Re: Blown BBC Swap final answers and opinions
Currently in the car attached to the v6.
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Car: 1990 Formula Firebird
Engine: 305 TBI (LO3)
Transmission: WC T-5 out of an 88 T/A
Axle/Gears: 10 bolt, 3.42 & Torsen Posi
Re: Blown BBC Swap final answers and opinions
V6 tranny won't bolt to a V8..... Do some more homework, the google machine is your friend.
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Car: '91 Firebird
Engine: 468 BBC w/ 8-71 blower
Transmission: Th400
Axle/Gears: 9-bolt 2.77
Re: Blown BBC Swap final answers and opinions
Ok well that takes care of one problem, I'll just throw 400 turbo in then and get a relocation crossmember for the torque arm, I've really only dealt with v8 cars so pulling this v6 is new to me. I'm aware that I have to move my motor mounts ahead. And as far as googling things that's what landed me here, I've read so many contradicting forums that I have come to the conclusion that I should just ask my own specific question to some guys who may have actual experience with these cars. Thanks!
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Car: 82 Berlinetta/57 Bel Air
Engine: LS1/LQ4
Transmission: 4L60E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Since your transmission plans need to change, why not a 4L80E? It's a TH400 with overdrive, lockup converter, and electronic (read: tuneable) control. More street-friendly, still strip-capable. Hooker also recently came out with a 3rd gen transmission crossmember that will support a 4L80E (or TH400) and moves the torque arm mount from tranny to crossmember, while providing room to route exhaust - pretty cool piece.
I don't have any personal experience with BBC in a 3rd gen, but I keep hearing Kooks and Lemon for headers.
I don't have any personal experience with BBC in a 3rd gen, but I keep hearing Kooks and Lemon for headers.
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#8
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Re: Blown BBC Swap final answers and opinions
Depending on how much you drive it you can go either turbo 400 or 4l80e. But remember 4l80e will need a trans controller. You could do a 700r4 but I doubt it would live long. Depending on how you drive it. Post a pic of that engine.
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Car: 92 Firebird
Engine: Supercharged 6.0
Transmission: T56
Axle/Gears: 8.8 3.73
Re: Blown BBC Swap final answers and opinions
The radiator from the V6 is bigger than 4th gen radiators. Def use the 4th gen fans
90-92 cars all got the V8 rad regardless of engine. Radiators got progressively smaller from 3rd to LT1 to LS1 cars
90-92 cars all got the V8 rad regardless of engine. Radiators got progressively smaller from 3rd to LT1 to LS1 cars
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Car: '91 Firebird
Engine: 468 BBC w/ 8-71 blower
Transmission: Th400
Axle/Gears: 9-bolt 2.77
Re: Blown BBC Swap final answers and opinions
Thanks I didn't know that about the radiators, I have two more brand new radiators for the v8 cars, but would it be able to cool the big block going in? And should I run a thermostat? I don't plan on doing any long road trips with this car mostly just runs to shows, cruising around town, if I can keep the 2.77 gears for a while that should make up for some of the gas mileage lost not having the overdrive, so I'll probably just stick with a turbo 400 rebuilt and modified.
468 8-71 blower
468 8-71 blower
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Re: Blown BBC Swap final answers and opinions
Thanks I didn't know that about the radiators, I have two more brand new radiators for the v8 cars, but would it be able to cool the big block going in? And should I run a thermostat? I don't plan on doing any long road trips with this car mostly just runs to shows, cruising around town, if I can keep the 2.77 gears for a while that should make up for some of the gas mileage lost not having the overdrive, so I'll probably just stick with a turbo 400 rebuilt and modified.
468 8-71 blower
468 8-71 blower
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Car: '91 Firebird
Engine: 468 BBC w/ 8-71 blower
Transmission: Th400
Axle/Gears: 9-bolt 2.77
Re: Blown BBC Swap final answers and opinions
You'd be correct, it's not currently in my third gen, you asked for a pic of the engine, that's the engine, it's just currently in a different car, I am trying to get everything ready on my third gen before I pull it from that car and install it in my car.
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Car: '91 Firebird
Engine: 468 BBC w/ 8-71 blower
Transmission: Th400
Axle/Gears: 9-bolt 2.77
Re: Blown BBC Swap final answers and opinions
It's a '66 Chevelle and thanks, I originally bought the engine itself and when I came back to help the guy pull it I brought my dad with me for extra help. My dad liked the car and bought it so we just brought the whole car home. We joke that I am just using the car as an engine stand until my car is ready. My dad plans to install a naturally aspirated 454 or 468 in it after my engine is out.
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Car: '91 Firebird
Engine: 468 BBC w/ 8-71 blower
Transmission: Th400
Axle/Gears: 9-bolt 2.77
Re: Blown BBC Swap final answers and opinions
Ok so after scrounging around the forums I've concluded that a stock V8 radiator with dual 4th gen puller fans along with a good air dam should keep this monster cool with no problem, going with a 400 turbo, relocation crossmember for the torque arm, still sticking with a stock 9 bolt rear end with 2.77 gears, now my only problem I think I have left so far is suspension, from what I've read I should definitely change out the old v6 springs or I'll be maxing them out on every bump. So does anyone have any recommendations for some decently priced street shocks and springs?
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