Cars » Gary Firch's 1981 TA- Butler Performance 505 cu.in Pump Gas Street Engine

Gary Firch's 1981 TA- Butler Performance 505 cu.in Pump Gas Street Engine

"Building My Super T/A"

On one sunny day in August of 1993, my eight year old son (Jeff) and I arrived at the local GM dealership. My 1991 GMC pickup needed some service work. Then Jeff spotted a car sitting in the used car section of the dealership. My son said to me, "Dad it's a black Trans Am, let's go check it out." We got out of the pickup and walked over to look at the car. I couldn't believe my eyes, it was a 1981 black and gold, 4.9 liter Turbo Trans Am. The car was in surprisingly good shape, it was a black diamond in the rough. I gazed into the window, and look at the odometer it had 26,725 miles on it. I then thought to myself this is too good to be true. A salesman walked over, and I asked, "How much for the T/A?" He then checked his pricelist and stated, "For $5,995 you can drive it away today." My reply to the salesman was, "You got yourself a deal."

I drove the car occasionally for year, then decided to freshen it up. I gave the car a frame off restoration, rebuilt the 301 C.I. motor, repainted the car, and replaced all decals/pin stripping.

I took my T/A to the local drag strip, interested in what it would in the quarter mile. It was sad to say that the performance of my 301 Turbo Trans Am was a heart breaker. The best time was 17.20 at 85.7 MPH. This car was about to undergo a serious power plant change.

I then checked my parts inventory, my choice being a 1973 455 C.I. four bolt main block. Along with other goodies that included the following: 1971 455 H.O. heads, mild solid lifter cam, a 850 CFM Holley carburetor, Holly street dominator intake manifold, and a turbo 400 transmission with a 2800 stall converter. Shortly after building this new engine combination, I took my T/A back to the track. As you might of guessed, I had much better results, with my best time being a 12.45 E.T. at 107.8 MPH. I was surprised, my T/A started to regain some of its lost image of being a muscle car. I finally felt that I had a T/A that looked great, and ran excellent. All was good until I did a tear down inspection of the motor. The lifter valley had several cracks in it.

After weighting my options of putting an old cast iron block back in my T/A, I realized this is not what I want to do. I thought to myself there must be something stronger that could with stand a larger camshaft and more horsepower.

I then heard about a speed shop in Leoma, Tennessee, from one of my friends who races Pontiacs. He then told me, Butler Performance can handle all my Pontiac high performance needs. So I called Butler Performance, and David Butler answered my call. We started to get an idea of what would be the best engine combination for my needs. David suggested a 505 C.I. Indian Adventures II block. I still wanted to use my set of H.O. heads on a trail basis. David mentioned that pump gas engines work well for customers who like to drive their cars on both the street and strip. I was very impressed with my 505 C.I. setup. The torque and horsepower output was a much needed change for the better.

I have heard that real horsepower is in the cylinder heads. I thought a pair of race ported B.P.. Edelbrock heads would be the answer. I called Butler Performance. and placed my order for the race ported Edelbrock heads. Once I received my new heads, I started to assemble my new power plant. I'm very pleased to say that every accessory bolted on and fit perfectly.

Once the engine was completely assembled, I took my T/A for a test drive. The torque and horsepower increased dramatically over my 455 C.I. H.O. heads.

Butler Performance helped me put REAL EXCITEMENT into my Pontiac. I am the proud owner of one beautiful l black and gold special edition 1981 Turbo Trans Am. I wish to express my thanks to, Jim & David Butler, Chase Milner, and also the entire staff at Butler Performance. I will always highly recommend Butler Performance, wherever my Trans Am and I go!

Thank You, Gary Firch

Update - 5/11/2011

I repainted my TA, changed the decals and gave it a new interior. The 505 is running great with no problems .The engine that you built is a source of great interest,as well as many questions about the installation and performance. I am having a good time going to car show, in 2010 the car won 24 of 27 shows I went to. In 2009 at the Trans Am Nnationals my TA finished in 2nd place in the modified SE-2 class, this year I am aiming at 1st place. I worked on the paint job and interior for the past 6 months and finished all the upgrade work on 5/11/11. My goal was to make it look like a brand new 1981 turbo trans am - Mission ACCOMPLISHED!

STREET/STRIP TECH. SPEC.
Year/Model: 81’ Turbo Trans Am SE
Race Weight: 4,005 LBS
Curb Weight: 3,780 LBS
Type of Fuel: 93 Octane B.P.
Engine: 2005 J.B.P. Indian Adventure II
Bore: 4.350
Cubic Inches: 505
Built By: Gary Firch (Owner)
Carburetor: 950 HP Holley
Jet Size Prim./Sec.: #80/#82
Spacer Plate: None
Intake Manifold: Edelbrock Performer RPM (Ported To Match Heads)
Fuel System 110 G.P.H. Holley Pump Regulator Set 7 P.S.I
Heads: J.B.P. Edelbrock 87 cc Race Ported Ferrea Valves 2.11 Int./1.77 Ext
Flow Numbers: 310 Int./229 Ext. C.F.M. @ .600 Lift @ 28” of H2O
Pistons/Rings: Custom Ross Flat Top/ Total Seal
Rods/Size: Eagle Forged Steel H-Beam/ 6.800
Compression Ratio: 10.8:1
Crankshaft: J.B.P. 4.250 Stroke
Rotating Assembly Balanced: Yes
Camshaft: Competition Cams Solid/Roller
Duration: @ .050 .270 Int/ .278 Ext.
Gross Valve Lift: 651 Int./ .651 Ext.
Lob Separation: 106.0
Center Line: 106.5
Installed Position: 2º Advance
Rocker Arms: Lunati 1.65:1 Roller
Ignition: Hypertech H.E.I.
Total Timing: 34º @ 2500 R.P.M.
Ignition Module: Crane HI-6
Headers: Ceramic-Coated Hooker Super Comp. 2” O.D. x 27” 3.5” Collectors/ 3.5” X-Pipe, Exhaust Pipes, Ram-AirRestoration Ent., Inc.
Mufflers: Xlerator By Goerlich
Transmission: T.C.I. Turbo 400 Super Street Fighter Auto/Manual Valve Body
Converter: 10” T.C.I. Super Street Fighter
Stall: 3500 R.P.M.
Shifter: Stock
Rear End: 10 Bolt Posi 3.73 Richmond Gear
Brakes: Stock 10.9” Disc Fr/ Stock Rear Disc
Tires: Firestone Firehawk P225/70R15 Fr. M/T ET. 26x10.5x15 Rear
Tire Pressure: 32 P.S.I. Fr./11 P.S.I. Rear
Suspension Fr.: Stock WS6 Package
Shocks Fr.: Monroe Gas Ride
Suspension Rear: Stock WS6 Package
Shocks Rear: Monroe Air Ride
Chassis Mods.: Lakewood Traction Bars/Comp. Eng. Sub-Frame Connectors
Interior Mods.: Hurst Line Lock Edelbrock Air/ Fuel Ratio Meter
Exterior Mods.: Decals/Pin Stripping By Phoenix Graphix
Safety Mods.: Driveshaft Safety Loop SFI Approved Flex Plate By T.C.I.
Paint Dupont 99A Black Single Stage, Painted By Owner
Launch Technique: Load to 2000 RPM
Estimated ET/MPH: 10.80/118 MPH