89FirebirdGTA35

iTrader: (1)

Longtime lurker here that has been a member here a bit and owned several thirdgens.

I've read the stickies and quite a few of the threads that Pocket/five7kid have posted on the subject.

I currently have a 1984 Camaro that use to be a LG4 and 700r4 that I am swapping in a bored to LS1 specs LM7, Performabuilt Stg 2 4l60e, Spohn Trans Xmember with the torque are and the hard joint, and 4th gen rear.

My question is when I go to do the fuel system in the coming weeks should I buy a replacement thirdgen tank since I've read that the carb'd ones had no baffle in the tank. Also would it be worthwhile if I did to just buy a bucket out of something like a 1990-1992 tpi so I could swap in an in-tank pump assembly and not go in-line. I plan on getting the Russell pushon/threadon fittings to adapt the Vette filter I have and the fuel rail.

I'm going to need all the pump I can get as the ironblock that's going in has a Torquer V2 BTR cam, ported and polished 799 heads, and will have a Fast 92/92 sitting on top for that end. I've pretty much gotten everything else figured out except the fueling issue, and I can't get a real answer on if i "have to" or if I can go in-line.

Sorry for the long post I'm just trying to cover all the bases before I drop the tank and realize I didn't have to.

Edit: I should also point out that I'm trying to keep everything in the car working like stock i.e. the gauges and things of that nature. Very first car was an 87 LT with a 305 and I'm retro modding this to bring back the feeling of that.

Thanks,
Chad

johnw999

I have a 1984 Trans Am, and I'm upgrading to a 5.3L LC9 and a T56 manual transmission. You can keep your original tank, but the fuel pump has to be upgraded. That means you either have to drop the tank, or you have to cut into the sheet metal above the tank. Some members are quite passionate about not cutting. I bought a plastic tank from a 2000 Z28 off eBay. Then I had a shop install the tank, a fuel pump access panel above the tank, and a braided fuel line. The 4th gen tank has an adequate fuel pump and an evap system. I can't tell if you want an inline pump or in tank pump. Both will work. In-line might be easier, but it's noisier too. Stock fuel lines may not provide enough fuel, but I don't know for sure. The shop that I used recommended a new fuel line.

Gauges - this is what I did to keep my stock fuel gauge:
https://www.thirdgen.org/forums/ltx-...x-sending.html

Mechanical speedometer - I just had this guy install a cable speedometer gear on my transmission:
http://t56cablespeedometer.com
He did a good job. I don't know how auto members tackled the problem.

oil and temperature are direct connections to a sensor, I think. Tach signal from the ecm needs to be converted. I haven't crossed that bridge yet.

grngryoutmyway

iTrader: (1)

If you are going to get a new tank anyways just get a fourth gen tank. I'm not sure if the lines coming off of it have the correct connects for the vette filter but you should be able to read through the fuel tank threads in the sticky to find out. You just need to change the float attachment to get the gauge to work correctly, but it can be had for like $20 on ebay now.

89FirebirdGTA35

iTrader: (1)

I plan on trying to find a used tank out of 99+ F-body after reading this and changing the sending unit. Good thing about that is now I can get a Racetronix drop in and use that and not have to worry about fuel like I did on my 98, after doing some digging do I need to buy new 4th gen straps or 3rd gen straps, also which filler neck do I need to modify the 4th gen or the 3rd??

grngryoutmyway

iTrader: (1)

4th gen filler neck just needs to be cut on the rubber a little, I just used the 3rd gen straps on the car, not sure if it matters or not.

johnw999

My fuel line.

Pocket

iTrader: (24)

The internal baffles arent that big of a deal. Just dont do any autocross level of cornering below 1/4 tank at WOT

If your tank is good, Id stick to a new sending unit with the threaded pressure fitting and a 96ish CK1500 5.0/5.7 vortec fuel pump. Youll have around $200 in the pair, drops in like stock and drives the stock gauge without mods

alan91z28

in my LS3 swap i used the 4th gen tank as can be seen in my swap thread...

https://www.thirdgen.org/forums/ltx-...gine-swap.html

there are pros and cons to both, i did like the direct fit, rust free worry of the tank itself, and good bucket for the pump, etc... i didn't care so much for the fuel tubing, etc

i think on my next LSx swap i am going to go with the 3rd gen tank with walboro 255lph pump and regulator up at the front

89FirebirdGTA35

iTrader: (1)

I ended up getting a tank it of an 02 SS, picked up he Racetronix pump and Hotwire kit for it. Going to use the PTFE braided line for fuel. I'm pretty sure I have everything I need now to finish slapping parts on t and getting it ready to fire. The only part I'll have left is to figure out the starter wiring since the previous owner was kind enough to cut some of the wires where they were. I'm sure I'll have to do some digging for it but the only schematic I've found that was close to mine was the austin guys diagrams.

89FirebirdGTA35

iTrader: (1)

I've read through a few old chiltons and Haynes manuals as well as the wiring schemes I've found online. What in the world is the wiring behind the passenger head, I'm wondering if I can just do away with it since its in the way of my tranny dipstick, I just can't figure out where and what it goes to. If it helps I'm ripping the hvac stuff out and have no need for it.

89FirebirdGTA35

iTrader: (1)

I forgot to post the video link.
https://youtu.be/Zrr6X5cSAoQ