Results 1 to 12 of 12
  1. #1
    Join Date
    Jul 2017

    1977 Trans Am LS1/T56 Build

    Hi All,

    I wanted to create a thread to log the progress of my 1977 T/A project. This project will be a slow moving project but the plan is to take my time and do this on somewhat of a budget. I'll give details on the car and what the plans are, etc.

    I've been an fbody guy for a long time, I've owned mostly 3rd gens. But about a year and a half ago a family member was moving and had this 77 T/A tucked away in his garage, I got it basically for a song, I know it's rough but this is the kind of project I've always wanted, 2nd gens have always been a favorite of mine, so this was too good of an opportunity to pass up. the plans for the car is to make it a well rounded driver / it will probably see very little track time, if any, but would like it to handle well in case the want to go racing arises

    The car is an authentic 77 T/A with the TH350 auto trans and W72 400 Pontiac engine. I was looking into what it would take to build up the 400 and do a manual swap and after doing all my research i decided doing a t56 swap to the 400 would make the most sense, but it looked like the best t56 to swap would be from and LS1 fbody car. so after finding a donor car for the transmission and doing even more research on my engine build, I decided that it was going to make more sense for me to do the whole LS1/T56 swap instead of worrying about building up the 400. I know that is going to make some people mad, but best band for the buck the LS1 just seems to make more sense for me (cheapness of building, fuel injected, decent fuel economy, etc, etc). so my donor car is a 98 Z28 car from TN that has just over 100k miles and is completely stock, the plan is to use as many parts from the donor car as possible and part the rest of it out.

    Mildly Built LS1 (lookin to get in the 400hp+ range) (Cam/Intake/Tune/exhaust/etc)
    Rebuild the T56 and upgrade to an LS7 clutch
    Upgrade Suspension for better handling
    Fix body issues (replace panels to remove rust issues)
    fix any broken interior pieces/panels

    I know this is super simplified plan, but ya'll get the general idea. The first step is going to be pulling the car apart and build a cart/dolly to put the shell on to start working on. after that I'll be figuring out what parts can be sold off and what needs to stay (engine/trans/etc) and then I can start on body work and so forth. excited to get started on this project. (the 98 is a salvage title car, so don't worry about me parting out a "good" car)

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  2. #2
    Join Date
    Jul 2011
    Istanbul / Turkey
    Country Flag: Turkey
    Looks like the U.S. version of my story. Beat up 74 firebird body with hell of a nice engine... What i can advice You is before You make the swap, upgrade Your pcm to a 411. 98 pcms are junk. They fry so easily while tuning. And with 411 You'll get far more parameters for precise tuning. If you want to go bigger, you can resleeve the block too.
    Being handsome is only skin deep. But Badass goes to the bone.
    Mert Celet

  3. #3
    Join Date
    Apr 2015
    Burlington KY
    Country Flag: United States
    looks like a pretty solid car compared to what i see around here. My Dad had a 78 when i was a kid as well as others. I saw one locally last year with an ls motor, they just attached the shaker to the hood.
    "Racing is life. Everything else is just, waiting"

  4. #4
    Join Date
    Jul 2017
    Quote Originally Posted by mert.celet View Post
    Looks like the U.S. version of my story. Beat up 74 firebird body with hell of a nice engine... What i can advice You is before You make the swap, upgrade Your pcm to a 411. 98 pcms are junk. They fry so easily while tuning. And with 411 You'll get far more parameters for precise tuning. If you want to go bigger, you can resleeve the block too.
    yea the 411 computer is on the list of parts to buy, I think the LS1 will probably stay stock regarding bore/stroke, but not 100% on all the details for that yet, I built a website for a local machine shop so they are building me an engine in return, I just have to contribute money for some parts.

    Quote Originally Posted by xsboost90 View Post
    looks like a pretty solid car compared to what i see around here. My Dad had a 78 when i was a kid as well as others. I saw one locally last year with an ls motor, they just attached the shaker to the hood.
    I'm hoping to make the shaker functional, we will see!

  5. #5
    Join Date
    Jul 2017
    On a side note, I am trying to get a parts list for my build and I keep avoiding suspension because that is one thing that I am just not the most knowledgable about.

    I would like to upgrade my suspension in stages if possible, currently the car is entirely stock, but everything is worn out, bushings are shot, I have a broken spring on the front passenger side, etc. first steps for the car is really to get it back on the road, and then later on down the road I will get it more performance oriented.

    I would like the car to sit a bit lower than stock, but with the aluminum LS engine that is going in it, I know the front suspension will have to have a little extra consideration put into that. any input on where to start would be nice. let's say I start my suspension budget around $1000-$1500, what can i get to help future proof it so that I can continue to upgrade in the future?

    any help is would be appreciated.

  6. #6
    Join Date
    Apr 2014
    DFW, TX
    Country Flag: United States
    I've run my '78 TA on factory control arms with 750# springs and double adjustable shocks on all corners and have done very well in autocross events. These cars also react very well to sub frame connectors- those need to be first so that when you get more grippy tires and better shocks you have a solid foundation.
    1978 Pontiac Trans Am Y88-R, DSE suspension, LS3/T56
    2002 Firehawk by SLP, LS1, 1LE

  7. #7
    Join Date
    Jun 2007
    St. Pete FL
    Country Flag: United States
    Nice project!
    it will be a great car when done
    1973 TA 4 spd #'s match red/white = STOLEN

  8. #8
    Join Date
    Jul 2017
    so Its been awhile since my initial post. I just wanted to give a bit of an update on everything.

    Back in March I decided it was time to start ripping into the 98, I pulled the engine and transmission out and dropped the engine off at the machine shop, they have finished all the machine work and it is currently just waiting to be assembled (I told them to not prioritize mine since the car isn't ready yet, so its just been sitting all these months), I'll give details shortly on what all is being done to the engine.

    The transmission is sitting in the garage waiting for my stage 2 rebuild kit to be thrown at it, The transmission had some minor synchro issues, but I figured while its apart I might as well upgrade, so I went with a stage 2 rebuild kit that should support 600+ hp. I also purchased a short throw shifter, a replacement slave cylinder with remote speed bleeder and a McLeod 1434005QD hydraulic conversion kit so that I can keep stock pedals and geometry while upgrading to hydraulic setup with proper brackets, etc.

    The 77 has its stock engine and transmission pulled and sold, I know a bunch of people will be upset about that, but I don't plan to re-sell, so to me its not worth taking up room keeping them. the subframe on the 77 was soft on the bottom (was literally sitting on them in the dirt), so I bought another subframe to clean up and modify to accept the LS1.

    Basically I've just been stockpiling parts, but here is the basic parts list and whats being done.

    1998 F-Body LS1
    799 Heads, professionally Ported and Polished
    Performance Valve Job
    BTR Stage 3 N/A Cam
    Adjustable double roller timing set
    High Volume Oil Pump
    ARP Rod, Head and Main Stud Kits
    Ported Dorman LS2 Intake Manifold
    Warr 92mm Throttle Body
    Bosch White 36lb GTP Fuel Injectors (flow 42lbs @ 58psi)
    99+ 0411 ECM
    Speed Engineering 1 7/8" Stainless Steel Headers
    Stock frame mount SBC motor mounts (will replace the inserts with poly ones at some point)
    Speedway Motors Solid SBC Engine site motor mounts
    Speed Engineering adjustable setback LS1 motor mount adapter plates.

    The Gearbox Stage 2 Rebuild Kit
    Diamond Stage 2 Clutch
    Aftermarket flywheel (haven't bought yet)
    McLeod 1434005QD hydraulic conversion kit
    B&M Ripper Shifter
    Tick Performance Slave Cylinder W/ Throwout Bearing
    Tick Performance Remote Speed Bleeder

    Next Steps:
    - strip, clean, modify, coat Subframe so that I can start installing new suspension components, engine, etc
    - remove interior (need to cut hole in floor for t56
    - remove old subframe
    - remove old fuel lines and brake lines
    - clean and underbody coat underside of car.
    - replace fuel tank with FI fuel tank
    - replace fuel lines
    - replace brake lines
    - replace suspension components
    - address brakes
    - address rear end
    - exhaust

    This is a large list, but after I get this stuff done I should be getting close to having it move under its own power. the main plan here is to get the car full assembled, get it driveable, and then once I get that all situated I can focus on body work / interior

    here is a google album with all the pics taken so far regarding the car

  9. #9
    Join Date
    Dec 2015
    Country Flag: United States
    Cool project, I look forward to seeing it come together!

  10. #10
    Join Date
    Jul 2017
    not a big update, but I got my motor back finally! below is my build sheet.

    Parts I provided for the engine:
    18lb Lightweight Monster Flywheel
    799 Casting Heads
    Dorman LS2 Intake Manifold
    Warr 92mm Throttle Body
    Speed Engineering 1 7/8 Long Tube Headers
    Bosch White 36lb GTP Injectors
    Stage 2 T56 Rebuild Kit (TheGearBox)

    Parts the engine shop provided for the engine:
    Sealed Power Gasket Kit - 260-1910
    - Head Gaskets
    - Intake Gaskets
    - Oil Pan Gasket
    - Rear Main Seal Gasket
    - Exhaust Manifold Gaskets
    - Valve Cover Gaskets
    - Valve Stem Seals
    - Water Pump Gaskets
    - Timing Cover Gaskets
    - Timing Cover Seal
    - Water Neck Gasket
    - Fuel Injector O-Rings
    GM Performance Parts Rear Main Seal - 89060436
    Felpro Timing Cover Gaskets - TCS45993
    Felpro Oil Pan Gaskets - OS30693R
    GM Performance Parts Valley Cover Gasket - 12610141
    Dura-Bond Cam Bearings - CH-23
    Clevite P-Series Main Bearings - MS2199P10
    King SI-Series Rod Bearings - CR865SI-10
    Cloyes Hex-A-Just True Roller Timing Set - 9-3158A
    GM Performance Parts Lifters - 88958689
    Moroso Racing Oil Pump - MOR 22120
    ARP Rod Bolts - 134-6006
    ARP Head Bolts - 134-3609
    ARP Main Stud Kit - 234-5608
    Pioneer Performance Freeze Plugs - PIO PE-496-B
    Hastings Piston Ring Set - HAS 2M4897
    BTR Stage 3 Camshaft - 33142122
    Pushrods - ? (have to find out what they used)
    Valve Springs - ? (have to find out what they used)
    Trunnion - ? (have to find out what they used)

    Work provided from machine shop:
    Disassemble & Inspect Engine
    Block Prep
    Hone Cylinders
    Grind Crankshaft
    Degrease Pistons
    Assemble Engine
    Remove Broken Exhaust Bolt
    Rebuild Heads
    Valve Job
    Port and Polish
    Camshaft Degree
    Rebuild Rockers with Trunnion Kit
    Paint Block
    Resurface Flywheel

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  11. #11
    Join Date
    Sep 2009
    Country Flag: United States
    Looks like a pretty solid project to start with. I did a very similar swap on my 1976 T/A several years ago and the 4th gen engine/trans/accessories fit very nicely. One thing I would do differently now than in the past is really researching the engine mounts. One thing that I really liked about the Holley stuff for my 68 Camaro is that they optimized the engine geometry to move the engine back as far and low as possible. I believe they do/did the same thing with the 2nd gen's too. Keep up the good work. I think you can use the 4th gen fuel pump assembly too with your stock fuel tank. If I remember correctly the 98's used a steel fuel tank so if you are handy with a welder, you could cut the top off and build a fuel tank recess to graft in the stock fuel pump. That would save you some bucks.

    1968 Camaro LS6, T56, Z51 brakes, 12 bolt, Speedtech, Hotchkis, DSE
    1976 T/A LS1, 6 Speed, C5 front brakes, and etc. SOLD

  12. #12
    Join Date
    Feb 2017

    For misc. body panels etc.