Originally Posted by rustfarmer
my first post,im new so bare with me.im building a 1929 dodge with a 1955 dodge hemi (270).im thinking of running a 700r4, a friend said 1st gear isnt any good on that trans ,i should use a 200r4. im using a 1989 dodge shelby decota rear. this is my first build ,with the help of a few friends ,witch can confuse things . any ideas or thoughts ? thanks
The 700R4 ratios are 3.06, 1.63, 1, .7
The 200R4 ratios are 2.74, 1.57, 1. .67
The 700R4 is more robust as it came from the factory it is a modified TH350 and is the parent of the 4L60 and 4L60E.
The 200R4 is a growth of the TH200 which was very problematic when put behind a V8 as GM tried as a money saving measure in the 1980's. The 200R4 has to be beefed up to handle being sandwiched between V8 torque and a weighty vehicle. Buick used them behind turbo V6s, but a smaller engine with a turbo has a gentler application of its torque curve than a V8. However, since you're talking a 270 inch old-time Hemi, this may work just fine. That's not the same as dropping a 350, 383, or more on the front of the bell housing. There are plenty of performance rebuilders and kits to beef the 200R4 up which in-spite of the small Hemi, I'd recommend doing.