301/455 weights; 79 Suspension

in my 81 bird (same setup as you) i used heavy duty springs from a truck. they took a bit of squeezing on the a arms to get the ball joints to thread but man is it awesome.

i think the springs were for a ford ranger of all things. with my small block in it sits high like there is no motor in it. and i can jump up and down on the bumper with 2 friends and it only moves 2 inches tops.

with a big block it would give one hell of a smooth ride and still be really firm.

in my case i have an original Z (WS6) code car, i replaced the 400 with an olds

455, i am using replacement springs for that model car and all is well, so just order springs for a 400 equipped car and you should have no problem, the 400 is by no means a light motor and the olds is damn near the same weight, and i am using an aluminum intake, as well as headers instead of cast iron exhaust manifolds, and my car is a manual vs an auto and the entire A/C system is removed, all of which will have a definate weight savings, but again you should be all set with parts for a WS6 79 T/A WS6 455 ,Hurst 4 spd, Blk w/ t-tops, Heavily Fortified, 4mpg 00 Ram 2500HD QC V-10 4x4,Blk,5 spd,4:10 LSD, 10mpg

98 Intruder 1400, Blk, 5 spd, 25mpg

I once had a '79 Espirit that had a 301. I swapped it for a 455 keeping everything else stock. The car sat around 1/2" lower in the front. To me it was perfect. The car still handled great and I had no suspension problems.

From what I remember, the 301 weighs about 475lbs and the 455 weighs close to 640lbs Stock its 165lbs difference, subtract the savings from your aluminum intake and headers and you're probably a lot closer to 100lbs difference. As for springs, why not just get a set made for a '79 400 T/A

As for the rear subframe, I've never heard that the T/A has a ladder type(?) I thought they were all the same.

Jay S

I thought they were the same too, when I read it i just went, huh?

Bird79

1979 Firebird Esprit 1973 455 YC

Check out the Hotchkiss springs. I've changed my suspension so many times I forget what all I've tried. They use a thicker coil and come in standard and 2 inch drop configurations. I'd recommend the 2 inch drop as it works well with an iron headed 455 and 235/60R15s for front tires on 15x7 rims. I'm a little lighter on the front end with aluminum heads, intake, water pump, headers, a 70 nose and a glass hood; the front height increased by about an inch with the 2 inch drop springs with the current configuration compared to a steel hood and iron heads, a bit higher than I would prefer.

So how do you like the car with the 455? It's been in for a while IIRC. ;^)

Which subframe is the book referring to? I'm assuming the rear subframe.

Dave

Thats got to be the worst riding car on the planet.

Best bet for a 301/455 conversion:

Put springs for a 455 or a WS6 400. A 301 is a lightweight compared to the bigger motors. The 301 is a thin wall casting and weighs quite a bit less.

That is why the 301 came into existence.

Lighter weight=Better fuel economy. In turn, lighter duty parts. Joe--ASE Certified Parts Specialist & 10th Ann.Club Tech Director '80 Carousel Red Turbo T/A, 26k orig. '79 "Y89" 400/4 speed 10th Ann. T/A, 57k orig '84 Olds 88 Royale Bgm 2 dr, 307 "Rocket" (lol), 141k and still going.... '80 T/A project car...

Joe,

I thought you quit posting here, that would be a loss. I finally got the tilt steering column to work in the T/A. You were right, there's a LOT of differences between a 75 and a 76; what a PITA, but it was worth it. Thanks for all the help.

Now to hijack this thread. I'm lost as to what to put on the shaker. Should it be 301 Turbo, 4.9L or 4.9L-Turbo?

Dave

Hi Dave. I'm here, but been busy, not gett "Turbo 4.9" on the hood scoop. That is for all 4.9 vin code T engines.

1979-81 Trans Am 4.9 liter non turbo (80-81) vin W Trans Ams said "T/A 4.9"

1980-81 305 LG4 engines said "5.0 LITRE"

1977 to 1979 403 and low po 400's would have said "6.6 LITRE"

1977 to 1979 400 W72 cars said "T/A 6.6".

Does that answer the question? :) 1976 is the last year you will see a CID displacemnt on a hood scoop. 1977 starts metric callouts. Joe--ASE Certified Parts Specialist & 10th Ann.Club Tech Director '80 Carousel Red Turbo T/A, 26k orig. '79 "Y89" 400/4 speed 10th Ann. T/A, 57k orig '84 Olds 88 Royale Bgm 2 dr, 307 "Rocket" (lol), 141k and still going.... '80 T/A project car...