87 formula 350 performance
Thread Starter
Junior Member
Joined: Aug 2008
Posts: 23
Likes: 0
From: Bacliff,TX
Car: 87 firebird formula 350
Engine: l98
Transmission: 700r4
Axle/Gears: 3.73
87 formula 350 performance
i have an 87 formula 350 and i was wondering what are some basic performance upgrades i should do to the car?
right now it has...
3" cat back exhaust
.30 bore
ported plenum
ported heads im assuming
accel super coil
right now it has...
3" cat back exhaust
.30 bore
ported plenum
ported heads im assuming
accel super coil
Thread Starter
Junior Member
Joined: Aug 2008
Posts: 23
Likes: 0
From: Bacliff,TX
Car: 87 firebird formula 350
Engine: l98
Transmission: 700r4
Axle/Gears: 3.73
Re: 87 formula 350 performance
yeah i was thinking about header cut outs...but i didnt know what kind of headers i should get yet
Supreme Member

Joined: Nov 2008
Posts: 1,545
Likes: 10
From: South Carolina
Car: 85 2M6, 87 'Bird 88 'burb
Engine: LX9, LG4, L05
Transmission: F23, 700r4, 700R4
Axle/Gears: 3.63, 2.73, 4.10
Re: 87 formula 350 performance
shorty headers would be easiest to install but long tubes would prob perform better, do you have to stay emissions legal?
Supreme Member

Joined: Nov 2008
Posts: 1,545
Likes: 10
From: South Carolina
Car: 85 2M6, 87 'Bird 88 'burb
Engine: LX9, LG4, L05
Transmission: F23, 700r4, 700R4
Axle/Gears: 3.63, 2.73, 4.10
Re: 87 formula 350 performance
my understanding has it that with most longtubes you have to pull the motor to put them in. Have you considered a cam swap? if you swap the cam put a good set of headers on it, you'll waste you money otherwise. I would go longtube, but thats just me.
Thread Starter
Junior Member
Joined: Aug 2008
Posts: 23
Likes: 0
From: Bacliff,TX
Car: 87 firebird formula 350
Engine: l98
Transmission: 700r4
Axle/Gears: 3.73
Re: 87 formula 350 performance
yes i would like to do a cam swap i just dont have the time to pull the motor my self but maybe i could get a local shop to do it
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Supreme Member

Joined: Nov 2008
Posts: 1,545
Likes: 10
From: South Carolina
Car: 85 2M6, 87 'Bird 88 'burb
Engine: LX9, LG4, L05
Transmission: F23, 700r4, 700R4
Axle/Gears: 3.63, 2.73, 4.10
Re: 87 formula 350 performance
Senior Member
iTrader: (1)
Joined: Feb 2007
Posts: 730
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From: Minneapolis, MN
Car: currently a 91 G92.
Engine: 305TPI
Transmission: Borg Warner WC 5 speed
Axle/Gears: 3.42
Re: 87 formula 350 performance
Also, a ported plenum doesn't necessarily mean ported heads. What is the basis for your assumption? You don't have to pull the engine out to install long tube headers. I would also consider a wide band tune. As far as the gearing is concerned, 3.73 I think is plenty of gear. What do you want to do with the car? This is the question you must ask yourself in order to decide which way to go. Thread Starter
Junior Member
Joined: Aug 2008
Posts: 23
Likes: 0
From: Bacliff,TX
Car: 87 firebird formula 350
Engine: l98
Transmission: 700r4
Axle/Gears: 3.73
Re: 87 formula 350 performance
yes i bought it that way...the owner was my dads friend and he said when they put it on the dyno it gained about 80 lbs of torque but thats just what he said
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Also, a ported plenum doesn't necessarily mean ported heads. What is the basis for your assumption? You don't have to pull the engine out to install long tube headers. I would also consider a wide band tune. As far as the gearing is concerned, 3.73 I think is plenty of gear. What do you want to do with the car? This is the question you must ask yourself in order to decide which way to go.
he said it was bored out so i assumed the heads would be ported but im still in contact with the old owner so i could ask him
as far as the car goes id like it the be a quick street car...maybe 12.50s somthin like that
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Also, a ported plenum doesn't necessarily mean ported heads. What is the basis for your assumption? You don't have to pull the engine out to install long tube headers. I would also consider a wide band tune. As far as the gearing is concerned, 3.73 I think is plenty of gear. What do you want to do with the car? This is the question you must ask yourself in order to decide which way to go.he said it was bored out so i assumed the heads would be ported but im still in contact with the old owner so i could ask him
as far as the car goes id like it the be a quick street car...maybe 12.50s somthin like that
Last edited by unibuga; Nov 26, 2008 at 11:08 AM. Reason: Automerged Doublepost
Joined: Mar 2000
Posts: 43,187
Likes: 42
From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Being bored .030" over (not .30" over) has nothing to do with ported heads. Rarely do they come together.
Hooker 2055HKR headers - emissions legal (and yes, you are required to keep it emissions-legal), best y-pipe out there for off-the-shelf headers. Only other choice to consider is from TGO member Dyno Don.
Hooker 2055HKR headers - emissions legal (and yes, you are required to keep it emissions-legal), best y-pipe out there for off-the-shelf headers. Only other choice to consider is from TGO member Dyno Don.
Thread Starter
Junior Member
Joined: Aug 2008
Posts: 23
Likes: 0
From: Bacliff,TX
Car: 87 firebird formula 350
Engine: l98
Transmission: 700r4
Axle/Gears: 3.73
formula 350
i have an 87 formula 350 i want to make it into a 12.50 street legal car.
and i will be driving it every day.
what should i do to it?
and i will be driving it every day.
what should i do to it?
On Probation
Joined: Oct 2008
Posts: 6,319
Likes: 19
From: Northern Utah
Car: seeking '90.5-'92 'bird hardtop
Engine: several
Transmission: none
Axle/Gears: none
Re: formula 350
I'm not going to venture an opinion without first asking some questions. Nitrous or no? Boost or no? Stock short-block or willing to upgrade if necessary? Modest rpm and loads of torque, or high rpm horsepower?
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What's the budget? What's it running now? Mid-15s?
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What's the budget? What's it running now? Mid-15s?
Last edited by Atilla the Fun; Nov 27, 2008 at 10:51 AM. Reason: Automerged Doublepost
Thread Starter
Junior Member
Joined: Aug 2008
Posts: 23
Likes: 0
From: Bacliff,TX
Car: 87 firebird formula 350
Engine: l98
Transmission: 700r4
Axle/Gears: 3.73
Re: formula 350
well its not running completely right yet but i was thinking headers intake and ecu first it should run mid 14s right now. i don't really have a budget yet ...id like to keep the stock engine just beef it up a little.no nitrous maybe a super charger if i can find a kit for it
Joined: Mar 2000
Posts: 43,187
Likes: 42
From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
You really don't need to keep starting new threads. I'm either going to merge them, or delete them.
Joined: Oct 2007
Posts: 2,606
Likes: 6
From: Kemah, Tx
Car: 1991 z28
Engine: Turbo 310
Transmission: T56
Axle/Gears: D44
Re: 87 formula 350 performance
bring it out to the friday night car show by highway 3 in league city tomorrow, and then to the show sat night infront of homedepot saturday in kemah so i can see it! ill be at both hopefully in my dark red 91z28
Joined: Mar 2000
Posts: 43,187
Likes: 42
From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Why do you have "LT1" in your user information?
Assuming this is a TPI car:
Cam, headers, Super Ram, whatever is required to support those.
Assuming this is a TPI car:
Cam, headers, Super Ram, whatever is required to support those.
Thread Starter
Junior Member
Joined: Aug 2008
Posts: 23
Likes: 0
From: Bacliff,TX
Car: 87 firebird formula 350
Engine: l98
Transmission: 700r4
Axle/Gears: 3.73
Re: 87 formula 350 performance
where on high way 3 is the show on friday
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