|01-13-2013 12:43 PM|
I think u r right. I took note of my truck rpm at 45 mph was loaing along @ 1400rpm
Thanx 4 ur input.
|01-13-2013 12:26 PM|
|dwwl||My 1977 nova had the 305 350 tranny with the 2.56 gears. NOw i have a built 355 200 4r 3.73 gears in it. Its a blast to drive in town, but i've got the better highway gear because of the overdrive. My toy only gets about 500 miles a year put on it and thats in town. I only take it out a couple of times a year to the big city. My tranny was not good, so I just built my 200 4r for a replacement because it gave me that option. I knew they were not as good as the 350 in stock form, so i built it up with the extra clutchs, bigger valves, stronger pump, widder band and ect. It"s a toy but it's been fun. I would recommend the 200 4r; maybe the 700 is better, but that is the way i wanted to go. I bett that 2.56 gears and 200 4r would not hardly let the motor get into its power band.|
|01-13-2013 10:28 AM|
I used to have an 89 Caprice with a factory TBI 305/200r4/2.56 combo in it. It would pretty much idle down the highway.
IMO the 200r4 has the best gearing of any GM auto, including the newer 6 speeds.
2.74:1 1st gear and 0.67:1 OD.
|01-12-2013 01:53 PM|
I have the pan, oil pichup and mountsfrom 25 YEARS ago. Planning on a heidts. Front end so it wont matter
|01-12-2013 10:34 AM|
|dwwl||In my case, thke 200 4r was a perfect fit. It allowed me to have my performance motor with my 3.73 10 bolt poss rear for my get up and go, with a highway gear. The second good part was that it gave a lower first gear than my 350 tranny, so it fells like i've got 3.90 gears. No matter what you do, have fun with it, you can change it again, and you will do that again in afew years.|
|01-12-2013 09:12 AM|
oil pan is not a problem.the new front end should accommodate a rear sump
If not,there is a kit that uses a 68 Buick center link that allows a rear sump pan.When you mount the towers for V-8 mounts,make sure the offset is facing rearwards not forwards,I made that mistake when working on my 65 when I was 17.I changed out the 283 foe a 327.back in the early 70s.buy good headers,,,,
|01-12-2013 08:55 AM|
|dwwl||Ithink i would be more concerned with that motor or any v-8 fitting without the different oil pan. You need to post to someone who has done that and find out that problem first, then work on that od tranny. that 200 4r is what I liked for mine.|
|01-12-2013 08:07 AM|
The 400 sb is from a suburban, sounds stock. My interest was the torque the engine should have. I like the OD trans for the steeper gearing to help launch the car and then if cruising the interstate gaining the advantage of the od. I just don't remember any Chevy 300 hp 327s ever feeling strong at take off withthe PG. With the od trans and this engine, why not just stay in 3rd until road road speed fast enough to let the engine lay at sub 2000rpm in od ? The rear end is not a posi-trac and I am only guessing the ratio is 3.08:1 . I will have to check to see what actual ratio is. I believe the 6cyl/pg was common with this gear. Thanx for all the comments/advise all have offered.
|01-12-2013 01:27 AM|
|01-11-2013 11:33 PM|
|vinniekq2||I stand corrected. the .7 o/d is 70 mph@1900RPM and the .67 over/d would generate almost 73 mph at 1900 rpm|
|01-11-2013 11:14 PM|
|cadillacdave1||1,900 rpm is fine. However. a 3.08 rear with a 200 R tranny and a .67 overdrive wont be at 1900 rpm. It would be much lower and wont run right. Why put an OD with 3.08 gears at all? OD is designed to bring rpms down on highway when using steeper gears. A 3.08 is not steep gear. I have run 700R 4 witha 2.56 rear gear -it doesnt work well rpms too low. Just my opinion|
|01-11-2013 10:50 PM|
1900 RPM=70 MPH with a 26.5 inch tall tire. what is wrong with that? My car has a solid roller cam,I can run at 2000 RPM with no problem at all. A mild to moderate 400 should be fine.
I dont like to say someone is wrong,but please state why an engine cannot run at 1900 RPM? The new gm cars are set up to run/cruise at 1300 RPM some cars have double overdrive
|01-11-2013 10:45 PM|
|dwwl||With 3.08 and overdrive your final gear ratio would be around 2.10 or so. That is so high that the vehicle will not perform, it will lug it self around and would drive poorly. With my 3.73 and 200 4r with its .67 over drive, it would like having a gear ratio of 2.50 and that is low enough because i run 255 60 15 tires. The only time i run it is when i'm above 60 mph and i lock up the covertor when i get to 65. I've know that some used it with 3.42 rear gears, but nothing below that, that i know of.|
|01-11-2013 10:29 PM|
|cadillacdave1||I dont think the 3.08 gears would work well with an overdrive. As I stated in my post, those gears wont, let the motor rev enough on the highway. He will be at 1400 rpm at 65 or 70. Why put an overdrive if keeping the 3.08 gears. The car already will run good on the highway. At .70 final gear in OD the car will ug and won't run right, it wont be in its powerband and wont get goof gas mileage. A car shoul run anywhere from 1800 to 2200 RPM on the highway.|
|01-11-2013 09:45 PM|
Why wont an over drive work with 3.08 gears?
The chevyII is 3100 pounds,no idea what is being done to the 400 sbc.The car is for the grandson,,,,
the power glide worked well with the 6 cylinder,it wont work less with the big V-8. My 67 chevyII had a power glide and 283 with 3.08 gears. Ive had 4 chevyIIs and never changed the gears with stock and near stock engines. 2 were pg cars,1 was a pg and converted to turbo 400,the 65 was a muncie 4 spd,all had 3.08 gears
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