I found this car, a convertible locally, that was already cloned into a T/A, in March of 2007. I was told that it was a solid 400 car. After getting the car I started disassembly and found that it had a '74 350 engine. That led me to go in this direction with this build. I've driven muscle cars back in the day when they were king and gas was .25 a gallon. I lost a couple of friends to wrecks, also. They were great in a straight line, but when the road turned, the cars wouldn't. I wanted to build a solid reliable car with modern a suspension, and the creature comforts of today. So here was the plan.

Frame off restoration with LS1/T56, corvette brakes, Hotchkis TVS suspension,and modern creature comforts for the interior.



I have been doing this build over the last 3 years and have learned a lot from this forum so I thought I would share my experiences with you guys and maybe help some here.

Sam

 

Here is the 74 350, and turbo 400.



I located an LS1 out of a 2002 Trans Am and a T-56 out of a 2005 GTO. I had the engine rebuilt by Nicken's Brothers racing engines. Nothing too radical, balanced, blue printed, heads ported and polished along with comp cam, hooker headers.



While the engine was getting done I had the frame cleaned up and powder coated and started setting up the front brakes. This is a C5/C4 setup. C5 calipers with a C4 Z06 rotor. I used 69 camaro drum hubs that I had turned down so the Z06 rotors would fit over them



Engine installed into the "new" subframe assembly. I used Carshop engine adapter mounts with small block chevy engine stands on the frame. ATS t-56 transmission brackett completed the install.







Sam

 

While the engine was getting built I had the body blasted and took it to the body shop.



Getting blasted


Dropping body off at the shop




Not quite as solid as I was told


New trunk pan


Wound up replacing the trunk pan, floor pans, outer cowl, repairing quarters and windshield, and cut out all the rust. Now I have a solid car.

6 months later I got the body back home and we are getting ready to mate the body back to the sub frame to test for clearances.





Sam

 

Awesome project! That car is going to be an absolute blast to drive.

 

Time to work on the rear end. After I got the engine installed I started on the rear end.

I pulled the rear suspension out of the car and was pleasantly surprised to find a corporate 8.5 under the car. The car had originally had a 2:41 open differential, so I installed a 3:42 gear set with an EATON positrac. Prior to putting the gears in I sent it off to get powder coated



LS1 Brake swap:

When I got the LS1 out of the trans am I also got the rear axle. My goal was to use the rear brakes. The major problem doing this mod was the 69 had staggard shocks and the shock on the passenger side interfears with the caliper bracket on the passenger side. To overcome this I sourced another driver side bracket and flipped it around so the caliper resides on the rear of the axle. The next issue was how to get the parking brake cables to pull from the same side. I took the left side bracket and ground the e-brake adjuster in order to re-use the retaining clip.



This is a picture of the retaining clips


I then flipped over the e-brake lever to pull from the rear. Now they both pull from the same direction.



This is a shot of the completed drivetrain:



The reason the drivetrain is off the car was to give me room to undercaot the bottom. I installed some eye bolts in the ceiling of my garage and hung the body so I would have access to the bottom. I used 3M body shutz for the undercoating.









Detail of the e-brake setup



[/QUOTE]

 

Thanks, 46Coup, your right!

Sam

 

Fast forward about 6 months to the spring of '09. Here are a few pictures of when I picked the car up after paint. The colors are Toyota super bright white with HOK oriental pearl blue stripes















Sam

 

While the car was being painted I picked up a set of Iforged 18x10 and 18x8 wheels from Tony a/k/a "Nineball". They came with NITTO INVO 275/40 for the rear and 245/45 for the front. He had purchased them for a vette that he had and decided that wasn't the look he wanted. I had some fitment issues and he and I worked out that I needed 275/35 for the rear and 245/40 for the front. Since he got the tires from Discount tire I went to my local store and the manager was kind enough to do a straight swap, I just had to pay for mounting and balancing.









Sam

 

Nice build!! That thing is going to be beautiful

 

Big Mat, thanks.

Sam

 

When I got the car back to the house I started the final install of the engine.

I used a PRC aluminum radiator, with a Lincoln Mark VIII two speed fan, synister products front drive system and wilwood master cylinder.

Wilwood master



synister front drive system



radiator



I decided not to use the GTO engine covers and went this route. Really sets off the white.









Sam

 

This was probably the most challenging and complex part of the build. As far as the engine, suspension and brakes, there are several companies that have done the engineering for the clearances brackets and what not, so it was a matter of doing your homework as to what system you want to go with.

For the interior I wanted all the conveniences of todays cars, but I also had a requirement that it look like it was made that way. Instead of opting to go with a custom interior built by an upholstery shop that looked custom, I wanted a factory look. My whole plan for this car was to build it under the premise that if GM had today's technology back in 69 with their styling of the day, what would they have done? I'm using all the 04 GTO electronics, PCM, BCM, PIM, and throttle control module, along with the factory wiring harnesses.

I chose to use the 04 GTO for my interior for two reasons. Number one was that the width of the dash was 54.5 inches and the width between the A pillars was 55 inches. The second reason was it's Pontiac and it looked really cool (ok so that's three). So let's begin

The first thing I did was cut away the 69 dash to make room for the GTO dash.



In order to locate the dash front to rear I used the shifter as my anchor point for everything to work off of. So I mocked up the console first.



I planed on smoothing the firewall so I used Vintage Air's Gen IV system for the HVAC. Here I used a couple of weld studs and welded them to the inside of the firewall to support the Vintage Air brackets. Now was the time to do this as everything was out of the way.



After setting the console I took the dash substrate and began to cut it to conform to the firebird cowl. Todays cars dashes are extremely deep so I had to cut away quite a bit off the front of the dash to get it to mate with the console. I lost the defrost vents but that was not a deal breaker. Once I was satisfied with the location and fitment, I welded brackets to the firewall and cowl in order to bolt the dash in.







The next thing I did was get the switches (Clutch position switch, stoplight switch and cruise control switches) from the GTO adapted to the firebird pedals.



Vintage air box fit with plenty of room.



Gauge Cluster and steering wheel



I also planned on using Electra Life power windows and locks. The GTO has only the driver and passenger windows that operate. The firebird has four windows plus door lock and power top. I had a company called Hzemall modify the console to accept all the switches. Again my criteria was that it had to look factory.



I was fortunate enough to have Vintage Air engineers help me modify the GTO A/C controls to work with their Gen IV system. So now the GTO ***** control the vintage air systems and again it looks factory.

 

Fast forward about 10 months. The car is painted and it is now back in my garage for final assembly.

Like I said before I planned on using the all the GTO electrical. I purchased a service manual for the GTO and began studying the schematics. What a nightmare. In order to keep the engine bay as clean and neat a possible I relocated the under hood relay center behind the dash. This took about 6 weeks of studying, cutting, soldering and heat shrinking.





The GTO dash is really two pieces. The substrate that is part plastic with a metal frame and the dash pad overlay itself. The next step to completing the dash was now fit the pad to the substrate. The first thing I did was remove the vinyl covering the pad so I could begin to trim back the front of the pad to conform to the substrate and cowl. The pad is made from plastic so it was a matter of cutting fitting cutting and fitting some more until I was happy with the contours.





Now things are starting to come together



Now, we can't have a GTO dash in a 69 trans am. I couldn't believe my good fortune when looking at the GTO name plate that it was almost the same size as a 67-68 firebird door emblem. So I ordered one from Classic Industries and substituted one for the GTO





You can also see in the above pictures that I relocated the a/c vent from the passenger do to the dash.

I just love the internet. I couldn't have GTO on the gauge cluster so I was able to find a company to make me a custom cluster face for the trans am. 1st gen firebird of course



Here is my new modern firebird dash

 

As I've said on Pro-Touring... car looks f'n sick!

 

Bonecrusher, thanks again.

Sam

 

Wow, that is a sweet ride that is about to get sweeter. Thanks for sharing.

 

This is the final phase of the interior to completion. Seats door panels and quarter panels.

For the quarter panels I took the original three pieces and bonded them together with rivets, resin and bondo



I then built some speaker rings to flush mount 6.5 Infinity Kappa speakers



I then covered everything with fleece and poured fiberglass resin over it. When it hardened I used a skim coat of bondo to smooth out the lines and cover it with the same material that was on the dash.



I used the GTO seats for the rear and modified them to fit the firebird by taking them apart and cutting the frames. On the back frames I cut off the top hoop as it was interfering with the convertible top movement. I then cut the bottoms in 1/2 and welded the frames back together to fit the floor.



sorry for the crappy picture of this view but the frames have been modified and now fit in the firebird.



I got the rear seats covered and started working on the space between them. After careful measuring I determined that I could use that space for a sub enclosure. I figured that I had just enough room for 2 8" subs. Here is the process on this project

I laid out the dimensions for the speaker and cut accordingly.



I then used poster board and marked the profile of the side of the seats and cut out the sides of the enclosure.



Then I cut 3/4 to 1" strips of mdf and screwed them to the top of the box. Sanded and filled the gaps to make a smooth top.



first test fit





Back in the 50's and 60's a lot of cars had a speaker in the center of the rear seats. Keeping in that theme I tried to emulate that look.

I laid up about ten layers of fiberglass over the top of the sub box. I then sanded it smooth to get this result







I then marked out the layout of how I wanted the "grill" to look and carefully cut it out of the fiberglass cap. This left me with a plug that I marked off a 1/2 width and cut that out.



I had a 13" sub speaker grill laying around from one of my sons stereo install so I cut the center out of it and laid it on the box and placed the fiberglass cap over it. I then bonded the cap back to the box and blended it in with bondo.



Covered the box in material and added a 69 glovebox emblem.










Sam

 

all it needed was a stroker 455 crank for that 350.

 

Try as I might I couldn't get the GTO seats to fit properly in the firebird. They were too wide and too tall. So I had to figure another route. Through some research I found some BMW M3 convertible seats. Took some measurements and I felt I could make them work. Here are some comparison shots









The seats are very comfortable and the have an intergrated shoulder belt for added safety

The door panels were another story. There was a lot of head scratching and I decided to try this method.

I cut the armrest off the GTO door and attached it to the firebird panel with rivets.



I then added florist styrofoam to the armrest and sanded to the shape I was looking for. I then added a layer of fiberglass and bondo to finish smooth. Turned it over to the upholstery guy and he did his stuff.












Interior completed



All the gauges work as well as the Driver Information Center in the gauge cluster. The only issue I'm having is the cruise control isn't working. I shows that it is on but will not engage. Oh well, I'll have to chase that gremlin down.

Driving the car is a ball. The seats are are extremely comfortable, power from the LS1 is great, although I'm not making huge power, it already sucked the doors off a friend's 69 bird with a pont 400 that was not stock, but the best thing is I'm getting about 23 mpg on the freeway. At 70 mph engine is turning just over 1900 rpm in 6th gear. I just love fuel injection. Suspension is firm and it drives like a new vette. Let me say from 1st hand experience back in the late sixties early seventies that these cars didn't handle the way they do now.

I still have a few more loose ends to clean up like finishing the trunk, get the cruise working and ironing out any electrical problems. This car is going to be a great cruiser.


Sam

 

Thank you performinnorman, (like the name)

Sam