5.3 Into 87 Firebird?: Grassroots Motorsports forum: Grassroots Motorsports Magazine

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Feb. 11, 2009 12:52 a.m. geomiata Reader

I was reading the thread on which engine makes big power for little money, and the L33 with minimal mods peaked my interest. One of my friends has a 87 firebird with a 305 and auto that he would sell to me for 1000 dollars. It has a shift kit, and a edelbrock performance carburetor, and headers.

How much work would i have to do to get a L33 with a hot cam, z06 valve springs, and the mentioned edelbrock carb into the car and running?? would the carb fit? what parts will i need?

thanks for answering my noob question.
Feb. 11, 2009 6:20 a.m. John Brown SuperDork

The carb would not fit without one of the VERY expensive intake manifolds and stand alone ignition system. To take advantage of this combo you would:

1: Sell the carburetor related accessories including fuel pump

2: Sell the headers

3: Buy F body headers for the LSX engine

4: Buy a new high pressure fuel system

5: Build 3.5" single exhaust because the F body does not have a lot of room for duals.

This swap can and has been done. The auto is not the best trans for the 5.3L swap but not terrible.
Feb. 11, 2009 7:05 a.m. Travis_K Reader

Yea, do it, but keep the EFI. Edelbrock carbs kinda suck as far as performance goes anyway, they are mainly popular just becasue they are shiny, and they will work farily well if you just bolt them on to whatever engine you want.
Feb. 11, 2009 10:25 a.m. patgizz Dork

keep the EFI with a LS1 car intake/fuel rails.

4th gen headers should fit, and you'll need the 4th gen F body oil pan, pickup tube, and windage tray. those 3 parts quickly turn a $700 deal into a $1000 engine. couple that with the intake, having to use car accessories to clear the hood(which requires a balancer and water pump change in addition to the accessories and brackets) and you may find yourself ahead just buying an LS1 takeout.
Feb. 11, 2009 10:48 a.m. P71 Dork

And for some weird reason actual 5.7 LS1 takeouts are getting cheap. I think everybody is jumping on the 6.0/LS2 and 6.2/LS3 bandwagon.
Feb. 11, 2009 1:46 p.m. geomiata Reader

this is quickly getting more confusing to me. i need the simplest way to get the engine running in the chassis. making it super fast and effecient comes later. in the words of michael scott, explain this to me like i am 4 years old.
Feb. 11, 2009 2:01 p.m. P71 Dork

Get an LS1 F-body take-out. End of story.

Because to put an LSx into an f-body you need the factory f-body oil pan, intake, front dress, etc anyways.
Feb. 11, 2009 2:12 p.m. ClemSparks SuperDork

I know you didn't ask this...but a good old "built" 350 would likely be cheaper. Find one you can hear run and drop it in with virtually zero other parts to change.

Speaking from someone who did it...the dipstick was literally the hardest part of the swap. I ended up with headers to clear the dipstick on an older 350.

Think about it, your fuel system will stay the same (keep your carburetor, fuel pump, etc), the transmission and torque converter will be good enough, as is, no changes in wiring, etc.

As much as I love modern efi stuff...if you're looking for the quickest way to have a faster (than a 305) F-body, an old school SBC is the low-hassle, low dollar recipe.

Clem
Feb. 11, 2009 3:13 p.m. oldopelguy HalfDork

Come on guys, the $700 for the intake manifold from Edelbrock and the MSD box that fires the coil packs really isn't all that bad a price. Especially when you factor in that I bought two running 5.3Ls rated at over 300hp with aluminum heads and barely 100k miles today for $300 for the pair. Maybe the manifold doesn't flow all that well, but if so it'll just handle more NOS, right?

You should be able to use exhaust components from a late-model Camaro, I think, and you'll have to scrounge up the oil pan as well. Aside from that you'll need to buy or fabricate motor mounts and if you want AC a new way to mount the compressor to the engine. That's pretty much it.
Feb. 11, 2009 4:10 p.m. patgizz Dork

oldopelguy wrote:

Come on guys, the $700 for the intake manifold from Edelbrock and the MSD box that fires the coil packs really isn't all that bad a price. Especially when you factor in that I bought two running 5.3Ls rated at over 300hp with aluminum heads and barely 100k miles today for $300 for the pair. Maybe the manifold doesn't flow all that well, but if so it'll just handle more NOS, right?

You should be able to use exhaust components from a late-model Camaro, I think, and you'll have to scrounge up the oil pan as well. Aside from that you'll need to buy or fabricate motor mounts and if you want AC a new way to mount the compressor to the engine. That's pretty much it.

couple that with the fact that the truck intake won't clear a camaro hood, nor will the truck's acessory system with the alternator setting up high. so you get fancy and try and fab an alternator bracket or you need to get F body accessories. which isn't just a PS/alt bracket deal, since they are different depths off the front of the block. so that takes a new balancer and because the water pump pulley goes with the pump you need the f body pump as well.

it gets expensive quick if your chassis can't handle the truck intake, accessories, or oil pan.