Gearing with 700r4
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4,713 Posts
Scott, if you're about to rebuild the rear end, just count the teeth and do the math that way, no guess work with that method.
10 to 1 its a 3.55. The gearing really depends on the combo and what you want out of the car(plan to do with it). If the gear you have now works well then stick with that. If you want a little more bottom end 3.73 to 4.10. give some cam specs and if you want to go to the track or not. On the overdrive thing. A gearvendor is a way better choice performance wise. The gear drop from 1st to 2nd in a 700 really kills em. And a 700 will not go into overdrive with your foot to the floor. Lots of other little things. We have one in are car and would not trade it for anything.
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1,018 Posts
Whether GV or not, skip the 700-R4 altogether and get a 200-4R. :thumbsup:
A 200 is a much better choice than a 700.
i have a edelbrock top end kit on my motor so my cam is the edelbrock cam
here are the specs
Operating Range 1500-6500 RPM
Duration Advertised 300° Intake/306° Exhaust
Duration @ .050'' 240° Intake/246° Exhaust
Lift @ Valve .560'' Intake/.573'' Exhaust
Lift @ Cam .330'' Intake/.337'' Exhaust
Lobe Separation Angle 112°
Intake Centerline 110°
Intake Timing @ .050" Open 10° BTDC
Close 50° ABDC
Exhaust Timing @ .050" Open 57° BBDC
Close 9° ATDC
i dont wind out to 6500 it shifts right at 5800 according to my tach.
i also have a 2800 stall converter
like i said its my daily driver and im just trying to get a little more perfromance out of it and better fuel milage
my main reason for rebuilding the rear is because its an open differential and im putting a posi. and while im in there im going with hp axle shafts and changing the gears
here are the specs
Operating Range 1500-6500 RPM
Duration Advertised 300° Intake/306° Exhaust
Duration @ .050'' 240° Intake/246° Exhaust
Lift @ Valve .560'' Intake/.573'' Exhaust
Lift @ Cam .330'' Intake/.337'' Exhaust
Lobe Separation Angle 112°
Intake Centerline 110°
Intake Timing @ .050" Open 10° BTDC
Close 50° ABDC
Exhaust Timing @ .050" Open 57° BBDC
Close 9° ATDC
i dont wind out to 6500 it shifts right at 5800 according to my tach.
i also have a 2800 stall converter
like i said its my daily driver and im just trying to get a little more perfromance out of it and better fuel milage
my main reason for rebuilding the rear is because its an open differential and im putting a posi. and while im in there im going with hp axle shafts and changing the gears
Don't know what tires you have but with my 3.42 rear and a T400 I was taching about 3600 revs at 80 mph on 985 this past weekend keeping up with two friends one on a Huyabusa and the other in a '04 Mach I that were taking me and the wife out to dinner.
The 200-4R with a .67 final gear would drop to around 2400 rpm at the same 80 mph.
Wouldn't that be sweet!!!??? Your 3.55 gear would be close to the same or higher rpm.
I actually love to drive my car and it is super reliable but I have got to get those revs down if I want to hit the interstate and make any long trips to the regionals.
Anyone know where I can find one? :yes:
Hope that helps in your decision.
The 200-4R with a .67 final gear would drop to around 2400 rpm at the same 80 mph.
Wouldn't that be sweet!!!??? Your 3.55 gear would be close to the same or higher rpm.
I actually love to drive my car and it is super reliable but I have got to get those revs down if I want to hit the interstate and make any long trips to the regionals.
Anyone know where I can find one? :yes:
Hope that helps in your decision.
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3.42 would be perfect with a 700R4 OD trans with your 530HP bbc that has plenty of trq for that gear & they will also be enough gear for decent strip perf too as long as cam wasn't too lrg/too much duration.
Heck,i have seen guys with fairly hot bbc street/strip cars running low 11's to high 10's with 3.31's.
But it also depends o n what you want,is reasonable over the road cruise rpm more important ,is strip perf more imoprtant to you,or is best comprimise between resonable cruise rpm and strip perf most improtant?
I think 3.42 with a 700R4 (esp with lockup set to engage at higher cruise speed like 45-50mph) would give you good over the road cruise rpm & fuel mileage vs decent strip perf with your bbc.
BTW,could consider a 200-4R that can also be built storng enough for your bbc that has better gear ratio steps from gear to gear if your serious about strip perf that i think can be setup to lock coverter at WOT but i am not 100% sure of that.
Scott
With the converter you have and the plans you have for the car. I would stick with what you have gear wise. Any overdrive trans has a lower 1st gear than your 400. So it's going to give it a little more bottom end with a overdrive trans as is. As a daily driver the most I would go with would be 3.73's. But I think the 3.55's would be just fine.
Personally I don't care for a 700r4 behind a BBC. They have a 3.08:1 1st gear ratio that makes 1st gear useless with big block torque.
2004r has a much better gear spread. And a better OD ratio. And swaps directly in place of a TH350.
My favorite choice would be a 4l80E. THey are basically a TH400 with OD. Same gear ratios, many interchangable parts, etc. It is the most expensive, but also the most reliable. Can be made to work electrically or fully manual with no controller.
IF it is mostly a street car and you have no desire for increasing power the best trans (bang 4 buck) in my opinon would be the 2004r. If you have 3.55's keep them.
2004r has a much better gear spread. And a better OD ratio. And swaps directly in place of a TH350.
My favorite choice would be a 4l80E. THey are basically a TH400 with OD. Same gear ratios, many interchangable parts, etc. It is the most expensive, but also the most reliable. Can be made to work electrically or fully manual with no controller.
IF it is mostly a street car and you have no desire for increasing power the best trans (bang 4 buck) in my opinon would be the 2004r. If you have 3.55's keep them.
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4,713 Posts
My 700r4 was picked do to my gear (3.08) and my beastly motor (283:boring
.
If you're looking for any mpg help you don't want to go with the 700 with it's very hot 1st gear. The 200-4R has better ratios and it'll have a nicer OD. Still a much better 1st to launch than the TH400.
I'm just sayin'....
.If you're looking for any mpg help you don't want to go with the 700 with it's very hot 1st gear. The 200-4R has better ratios and it'll have a nicer OD. Still a much better 1st to launch than the TH400.
I'm just sayin'....
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2,098 Posts
my 700r4 is living just fine behind my 496/607hp/627ftlb (at the crank) motor. the trans was built by local who knows his stuff though and put the right things in it. I run 3.42 gear with 275/60r/15 rear tires. imho it is the best of both worlds. the low gear is a monster and the od is great. 65 mph = 2200 rpm +/-....
my car came with a 396/325 motor, powerglide and 3.55 gears in the 12 bolt posi.....67ss396....it is a much better combo nowadays.
my car came with a 396/325 motor, powerglide and 3.55 gears in the 12 bolt posi.....67ss396....it is a much better combo nowadays.
If your looking at about the same cost. The GV is a no brainer. I have had one in my car for 10 years and I have never had a problem with it. Its a lot more fun the a OD trans. With a 3 speed trans you really have 6 gears. You dont have to use them all of the time but it is fun to play with. Mine is behind a powerglide, but I have been in the 9s through the 1/4. If I cant tear it up then that one tough gear box.
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