I found a 71 formula now its it oretty good shape on the outside and stuff the frame and floors feel fine,what i wanted to do was covert it into a trans am useing my 74 SD-455 t/a parts car (it was rolled and filled with bondo real bad).How hard would it be to use a 305 4bbl from a 85-86 z28/ta? what problems would i run into? if any at all.This would be a daily driver.

 

please change the avatar some people might find it offensive and it could get you banned

Paul

 

hahahaha some people.... i find it hilarious.

 

That wasen't part of my question but sure

 

Should be ok. New manifild and carb...Might be a bit low on horsepower.

I had a 76 Formula 400 4bbl. for about 10 years. Was atleast 20 years ago or so.... Doors were so heavy they poped open over bumps. One day I was kinda on it and the door popped open on a hard right turn. I was leaning against the door some and when it did the seat rail snaped on the inside and the car tried to launch me out the door. I lost control and spun out a few times. I tried to get back in, it kept trying to throw me out. Only thing hurt was my pride and some pulled muscles from tring to keep myself from the blacktop. Seatbelts don't help in this situation. Doubt it's a common deal but man it was the freakiest thing I ever had happen to me. keep them door pins dealt with..lol

 

I don't fully understand your question.

You want to use the parts from an SD for the '71, or you want to install a 305 in the '71?

Frankly- anything to do regarding changing to a non-Pontiac engine in the '71 will have issues:

Exhaust manifolds and possibly pipes
engine mount locations on k-frame
basic plumbing- i.e. hose placement/shape
fan shroud misfit
shaker placement/height
transmission mismatch (bolt pattern or crossmember issues depending on what's being used)



The easiest thing to do is replace the Pontiac engine in the '71 with the Pontiac engine from the '74. Any installation of another division's engine (i.e. Chevy) will cause problems which will only have to be reversed when you do go to put a Pontiac engine back in.

 

well late second gen pontiacs use the 301 so that should have the same bolt pattern shoulden't it? i don't want a motor that gets 10mpg highway...I want to make a daily driver.

 

There is no reason why you can't get reasonable mileage out of the pontiac motor. Why would you want to butcher a rare classic.

Keep your Pontiac all Pontiac and get a Honda for a daily driver.

HardCore Hot Rods

 

I woulden't be butchering it , i would keep the original motor,and besides its sat for about 10 years and some punk made cut outs for subs in the back seat,Get a honduh? hell no i like driving daily with some style and torque.

 

My point exactly. You'd be taking a real step back for nothing with a 305 swap.

10 yrs is nothing. Rear seats are replaceable. Tons in the wreckers. 70/81 Fbird can be recovered in the origional material.

As soon as you yank that Pontiac motor the value of that classic muscle car will go right in the toilet.

The pontiac motor will not be bad on gas. The smog punked
305 will not be better enough to justify the work.
If you really have a 71 formula ya need to re-think that one.
The car is worth $7000/10,000 restored.
74SD455TA is worth more. You'd be throwing a lot of money out the window by butchering either of them.

 

yeah i am still confused on what this guy has or doesnt have.

but either way, F-BIRD is right, dont put a 305 in a classic 2nd gen. both a 71 formula and 74 SD TA, especially the SD, are desirable cars. if you like torque its tough to beat a pontiac 455.

 

also....those 74 SDs are pretty rare....i dont think there were too many of those units made

 

Look to the right of this pic see that white rusty thing,yes that is a 1974 SD-455 t/a the motor and tranny are laying on that field and have done so for at keast 15 years the car was rolled,both 1/4panels have an easy 3 paint cans worth of body filler...they found a old early 70s firebird and used the hood and front nose,the sd-455 motor matches the cars suffix codes even has the original interior but again too much work...my g/f lives in hamilton i live in brampton i need somthing that will get decent milage but still looks mean,somthing V8.

 

One thing most people forget about:

Except at idle speed- a larger engine does not necessarily get worse gas mileage if you're comparing like-for-like systems and driving habits- i.e. same transmission, rear gear, induction system, how hard/often you hit the throttle.

A larger engine would tend to generate more torque and hp- but if you drive the vehicle without putting your foot into it- you would actually get about the same gas mileage with a larger engine. Why? It generates alot more torque and HP- so you don't have to hammer it up to 2000rpm to get it rolling- maybe only 1200 by comparison to have the same torue being generated. At highway speeds- you have more available torque/hp so cruising at 100km/h means you may be barely touching the throttle (if set-up properly, higher-rpm cruising will run the mixture on the lean side). When sitting at idle, flooring it, or continuous stop-go driving is primarily when you will see large differences in fuel consumption.

Another reason people find they get poorer mileage with larger engines is that they tend to develop the heavy foot syndrome. I fall for this all the time. Put me in my 305-powered Monte Carlo and I'll drive [relatively] normally. Put me in my 2nd Gen. bigblock-driven only in the summer- I can't keep my foot off the gas.

Just as an example from my own personal experience I get about (I actually track gas consumption vs. mileage continuously):

13mpg city, 17mpg highway in my '79 Deville w/425ci Caddy engine (car weighs about 4000lbs)
13.5mpg city, 17.5mpg highway [formerly] in my '81 Monte Carlo with a Chevy 350 (car weighs about 3700lbs)
13.2mpg city, 16mpg highway in my '81 Monte Carlo with a Chevy 305 (car still weighs about 3700lbs) -removed the 350 to use in an '87 SS I will eventually get around to completing

-all the above have 3-speed autos (TH-350 in MC, TH-400 in Caddy), 2.25 rear gear in Caddy, 2.41 gear in MC, Caddy runs 15" wheels, '81 MC uses 14".

Look at this another way- even if you saved 25% on overall fuel costs by going with a smaller engine (not likely)- what's gas cost? $0.75/L we'll say. SO- you'll save 18.75 cents a litre. How much gas do you actually go through in a month? Do you have to purchase another/smaller engine to do this swap? What other parts will have to be purchased to fit it all up? Let's say materials/parts alone will cost you $250.00 (we're assuming you have most of the parts already). $250.00 has to be paid by saving 18.75 cents a litre- that equals 1333 litres have to be bought before you start to actually "save" anything. Translate that into full-tankfuls (20 gallons) for the '71 T/A and that will be 17.64 complete (empty to full) tanks- after that you will then start to save money on gas- all the while driving a setup you may not like anyways.

As stated above- if gas mileage is a primary concern- you really are barking up the wrong tree with a 2nd Gen. f-body- get that Honda or a 20 year old Chevette- they're both lightweight, available with manual transmissions and have teeny-tiny little engines. Hell- the Chevette is even a rear-wheel-drive.

 

excellent point, Eric. gas milage car vary signifcantly with how you drive your car. for those of us with carbs, if you stay out of the secondaries you will get decent milage, especially with a Q-jet (assuming the carb and the rest of the engine is tuned properly). notice that Eric's 350 even got slightly better milage than his 305 when in the same vehicle.

 

Less throttle resonce required, even with bigger cubic inches or a better running engine will get better fuel mileage. In a lot of cases, when a person installs smaller jets which make an engine run leaner it will cause the operator to use a higher amount of throttle. On the highway that might be cool but in places where a little torque is needed the fuel mileage falls drasticly because of the need for more throttle. Fuel management is the key to the equasion. not weither it's a 350 or 400 CI in some or most cases.

 

The 71 formula is better and worth more than a butchered hogpog of parts. The formula had exactly the same suspension as the ta in 71 All the TA hi perf motors were available in the Formula. The formula also came with a 350ci in motor.The 71 formula would be way too cool as is with what ever pontiac motor is in it. I know cause I had one.
People loved that car. It would be punk with a 305 in it.

Mine had a 400, a 454 BBC and a 350SBC....

 

dreamer.

 

That was the best reply yet!!!