which transmission did u choose and why?700r4?th350?th400?
08-18-2009, 04:09 PM
#1
which transmission did u choose and why?700r4?th350?th400? still undecided on what transmission to use for my build. either a th350, th400 or even a 700r4. i will only drive it on the weekends on highway for sure. just want to make sure its at low rpms at high gear. Also anyone know the spacer part number to bolt the transmission to a 2003 5.3 engine? And will the convertors on the transmissions bolt holes match up the flexplate?
08-18-2009, 09:36 PM
#3
I want to drive on the expressway as well and thats the reason im going 4l60e, i've got a nicely built 400 that i'll use on another build; unless my buddy sells his 2004r; built to the hilt by cpt in Cali. 3 speeds are for STREET & STRIP only imo.
08-18-2009, 11:24 PM
#4
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I chose a T56, just because (just my opinion) a performance car should always have three pedals - but like I said, that's just my 2c. I felt like the manual gives me greater control than an automatic, & the six speeds offers maximum flexibility, especially for what I hope to be doing with the car (racing on the salt, road courses, & hopefully even some open-road racing!).
With that said, I know that you'd prefer to limit the discussion to the autos mentioned above, & if I were to choose between them, I'd have to give the nod to a properly-built 200-4R, like what was OE in the Grand National Buicks, etc. You get four speeds & the ability to handle a pretty decent chunk of power. If that's not in the budget, I'd have to think about it a bit... The 700R4 is a decent trans, but I just don't know about durability when you get over about 450 hp or so. The TH-350 & TH-400 are really good transmissions, but that 1:1 top gear is a PITA on the highway if you have any decent gears. I'll be interested to see what others have to say on the subject!
Good luck.
With that said, I know that you'd prefer to limit the discussion to the autos mentioned above, & if I were to choose between them, I'd have to give the nod to a properly-built 200-4R, like what was OE in the Grand National Buicks, etc. You get four speeds & the ability to handle a pretty decent chunk of power. If that's not in the budget, I'd have to think about it a bit... The 700R4 is a decent trans, but I just don't know about durability when you get over about 450 hp or so. The TH-350 & TH-400 are really good transmissions, but that 1:1 top gear is a PITA on the highway if you have any decent gears. I'll be interested to see what others have to say on the subject!
Good luck.
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08-19-2009, 02:26 PM
#9
I chose the 4l60e, it came with the motor and is designed to work with it and the computer. The 700R4 is a non-electric 4l60e, so I don't see a good reason to go with that. You would have to figure out the TV Cable linkage which you would not have to do with the 4l60e. Same for the 2004r. My car is a cruiser, but with my 2800 stall converter and 3.80 gears it has some performance when needed.
Pat
Pat
08-19-2009, 02:36 PM
#10
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it'd help a lot if you mentioned what you are building and how you plan to use it... you mentined driving on the highway, but is that ALL you are going to do with it??
If all you are going to do is drive on the highway and you don't care how long it takes you to get up to 70mph, then TH350 and like a 2.56:1 rear gear would be a good combo.
If you want to hit the drag strip occasionally or just raise hell between stop lights, and also want decent MPG on the highway, you want a 4-speed overdrive. The 4L80E has better gear ratios, but it's also a bit heavier. The 4L60E has a stupid 3.06:1 first gear, but it's tolerable. I wouldn't run anything with a @#%*&! throttle valve cable.
If all you are going to do is drive on the highway and you don't care how long it takes you to get up to 70mph, then TH350 and like a 2.56:1 rear gear would be a good combo.
If you want to hit the drag strip occasionally or just raise hell between stop lights, and also want decent MPG on the highway, you want a 4-speed overdrive. The 4L80E has better gear ratios, but it's also a bit heavier. The 4L60E has a stupid 3.06:1 first gear, but it's tolerable. I wouldn't run anything with a @#%*&! throttle valve cable.
