What should I do?

[Omnivium]

hello; What's the transmition in that car?
IBBY

I think the 200-4R? Not sure. It's stock. 4 speed automatic and it's an overdrive transmission.

 

[Clone TIE Pilot]

Your single biggest acceleration improvement & bang for buck will come from a rear end/gear swap. Other than that I would just get an old school performance oriented shop/mechanic to put in an advance curve kit and give it what timing you can, to get it peppy. You will pick up some noticeable power here but mostly you gain responsiveness. It will/can feel eager not sluggish and pull stronger longer without falling on its face. (Unless your Q-jet is in need of a rebuild) Last I would add a cheap Summit or Jegs brand cat back exhaust system mostly for a nice low v8 rumble. Beyond that keep your money for something else.

You both should have a 200-4R if its factory original. You both have 15" wheels. A stock 307 won't accelerate any quicker in the 1/4 mile if you run it past about 4,100 rpms in 3rd gear. So a 3.73 is about the best gear even for its relatively poor power mostly because it doesn't make any more power beyond that with the stock heads & cam.

With stock 26" tall tires a 3.73 will turn 68 mph in overdrive at 2,200 rpms.
With 28" (275/60/15) a 3.73 will turn 73 mph in overdrive at 2,200 rpms.

I had an 88 307 with 2.56s. When I changed to a 3.73 it got a lot quicker and would burn tires at a stoplight easily. Mileage in town got better but fell on the interstate. Overall mileage stayed about the same for me.

http://www.wallaceracing.com/calcmph.php

Any 3.42, 3.55 or 3.73 would be a good choice with little difference between them but a noticeable jump coming from 2.56s or taller. (lower numerically)

Stock dist is computer controlled, would need a custom PROM with a hot spark curve. Still can try bumping up the base timing? It works well for SBC 305s, not sure about SBO 307s?

 

[Omnivium]

Your single biggest acceleration improvement & bang for buck will come from a rear end/gear swap. Other than that I would just get an old school performance oriented shop/mechanic to put in an advance curve kit and give it what timing you can, to get it peppy. You will pick up some noticeable power here but mostly you gain responsiveness. It will/can feel eager not sluggish and pull stronger longer without falling on its face. (Unless your Q-jet is in need of a rebuild) Last I would add a cheap Summit or Jegs brand cat back exhaust system mostly for a nice low v8 rumble. Beyond that keep your money for something else.

You both should have a 200-4R if its factory original. You both have 15" wheels. A stock 307 won't accelerate any quicker in the 1/4 mile if you run it past about 4,100 rpms in 3rd gear. So a 3.73 is about the best gear even for its relatively poor power mostly because it doesn't make any more power beyond that with the stock heads & cam.

With stock 26" tall tires a 3.73 will turn 68 mph in overdrive at 2,200 rpms.
With 28" (275/60/15) a 3.73 will turn 73 mph in overdrive at 2,200 rpms.

I had an 88 307 with 2.56s. When I changed to a 3.73 it got a lot quicker and would burn tires at a stoplight easily. Mileage in town got better but fell on the interstate. Overall mileage stayed about the same for me.

http://www.wallaceracing.com/calcmph.php

Any 3.42, 3.55 or 3.73 would be a good choice with little difference between them but a noticeable jump coming from 2.56s or taller. (lower numerically)

Wait so I can just change my gears instead of like the whole rear end? Haha sorry I'm a noob

 

[UgotBronx]

It made all the difference in the world! I was a hazard to others when trying to get on the highway before i change out the rears. It was the very first thing I did when I bought the car..I never had an issue at those speeds.

I wanted to keep the OG 307 in mine and I did all of what has been suggested here. Dual exhaust & headers, 373 gears, QJET rebuilt once then i put on the edelbrock 600. The most noticeable upgrade was the rear and the exhaust. rear still going strong but the headers and exhausted lasted just about 5 years so if that works for you then invest the $$. GOOD LUCK!

When you went 373's in the rear, how does she run on the highway at 70-75mph. I have 256's in the rear and its dog slow off the line., looking to go. Either 3.42' 3.55 or 3,73. But concerned about it spooling 3000 rpm on the freeway. I have a 4 speed 200r4

 

[UgotBronx]

Awesome recap there dogshit! Yes you are right on all accounts.. I did advance the distributor for a little more snap.

And yes Omnivuim you can just change the guts/ gears Did the same in my camaro too

 

[Omnivium]

Awesome recap there dogshit! Yes you are right on all accounts.. I did advance the distributor for a little more snap.

And yes Omnivuim you can just change the guts/ gears Did the same in my camaro too

Oh wow didn't know that! Learn something new everyday lol. Is it a major job? What gears would I be looking at to get? 3.73?

 

[horners85regal]

i actually went to the scrap yard and got my 3:73 gears out of an s10 and a posi carrier out of a monte ss, total cost was 75 bucks.

 

[Omnivium]

i actually went to the scrap yard and got my 3:73 gears out of an s10 and a posi carrier out of a monte ss, total cost was 75 bucks.

What exactly is a posi carrier?

 

[horners85regal]

when you pull your diff cover off the piece in the center with the gears in it and the ring gear around it. thats what you would change out to make both your rear wheels go instead of the one wheel peel. i figured if im pulling the stock carrier out to change my rear gear ratio then may as well find a posi unit for it too !

 

[Omnivium]

when you pull your diff cover off the piece in the center with the gears in it and the ring gear around it. thats what you would change out to make both your rear wheels go instead of the one wheel peel. i figured if im pulling the stock carrier out to change my rear gear ratio then may as well find a posi unit for it too !

So if I change gears I should do that too?