what engine now?

on flat land yes, 1800rpm good but if you have rolling hills, like i have here. you need about 2200 rpms. that way when you hit the hill, you have some room for the rpms to drop before you have to down shift out of over drive.

where my state. you are going down or going up a hill . if you do find flat land, it for very short time.
with 3.73 gears in our cars/trucks with 27" to 28" tires. you get to stay in overdrive on every thing but the very steep grade hills.
with overdrive , those gears are like 2.50 to 2.56 gears. gas mileage is not a big hit, in some cause's. it have improved 3 to 5 mpg highway because your tranny not down shifting, then up shifting on ever little bump in the road. which is hard on overdrive your tranny.

 

Better check your math. The stock 200-4R trans in that car has a 0.67:1 fourth gear. With the stock 225/75-15 tires (28.29" OD) and 3.73:1 gears, I'm showing 1782 RPM at 60 MPH in fourth.

 

sorry but we drive 75mph here because thats our speed limit!
if you drive 60 here, you get run over by every semi.

 

Nevertheless...the 2004R does have a high 4th gear....that's how you get the mileage out of that car. Interesting note though....that tranny has a very LOW first gear that gets out of the hole very well.

 

In which case, mileage is not your top priority. In any case, even at 75, the engine would only be turning about 2200 RPM.

 

My 92 Roadmaster has 3.23's and the larger 28.6" 235/75 tire, I turn 2000 at 65mph and 2400 at 75mph. There is a guy here in Erie, that works in the shop next to mine, with a 94 Caprice wagon running 3.73 and he said he is turning 3200 rpms at 75mph with 225/75 tires. The 3.73 is way to low for my commute and terrain, where 3.23 is about perfect. Though mine has a 700R4 tranny and his a 4L60(basicly the same thing) its still a 4 speed with very comparable ratios.

Ratios for my 700R-4 are
First - 3.059:1.0
Second - 1.625:1.0
Third - 1.000:1.0
Fourth - 0.696:1.0

 

correct, that what i been saying. that mileage is part of the complete package. i'm looking for(like i been saying) to make the buick run just like my last two caprice's. 23/25mpg highway and still have the passing power to over take slow traffic easly. i'm still needing to know which olds/buick engine will give me that? or should i just find a engine Drive train from a caprice and call it good?

 

Ok this is gonna sound odd but pull the plastic cover that goes under the torque converter then run the engine and see if you hear the noise. It will rub there and sound like an engine knock. You might not need an engine.

 

Well now, there's some good advice. That IS a common occurrence on these models. And...if, indeed, the engine has only 93K on it...it's unusual for a 307 with that mileage to spin a bearing unless misused. Uhhh....like pushing cars around..... Or over revving it etc.

 

the car does have 93,000 miles but it sat for the last 10 yrs and it has class 4 hitch, so who know what miss use the PO'S has been through.
when I have some free space in the therapy room ,I will check out the little 307 that could.

 

I will be interested in hearing what's up with that engine, ranch.

 

The engine that will get you closeset to your goal with the least work will be the Oldsmobile 350. Next choice would be the 403 although the mileage will take a hit. Your cars 2.73 axle ratio will help in the mileage department. The larger displacement will help in the power department.

Build the engine with 9.5 or so compression, a true dual exhaust (your Caprices had that if they were LT1's) and supertune it. You could also keep the factory feedback carb and ingnition timing control but that would take some of the flexibility away to tune it.

If you wish to discuss specifics in private chat, I can be more detailed.

 

yes the 307 is no good:banghead3:. I took it for a 30 mile round trip today and when I got back. you could hear the front set of rods rattling away under light load, so the hunt begin for the replacement.

 

3.8 turbo Buick keep it real

 

Excellent Idea!! I was just thinking the same thing.