1964 Chevy Impala Project: Swapping out a 327 ci for a 350 ci crate. Currently running a TH350 transmission. I know that the TH350 is a good matchup for the 350 ci, but if I wanted to upgrade the TH350, would a 700R be a good choice? Thanks in advance
Th2004R has the best gearing. No need to change out unless you want better acceleration. Plenty of 5Klb 80s Bbody wagons with 28" tall tires, 2.41FD and brick aerodynamics cruised the freeways at speed with anemic 305/307 engines.
Although I do not consider myself a GM guru from my experience the turbo 350 or the turbo 400 transmission or the powerglide are all almost indestructible transmission behind a modest powertrain I would rank them as some of the best automatics ever made. That's being said they were made for a much slower America back when interstate highways were 65 mph and when you got in City areas you were doing 45 to 55. Unfortunately we do not live in that era anymore there is no federally mandated speed limit some states you might be doing 85 miles an hour on the highway legally, in my state of California 70 mph is legal, a non overdrive automatic tend to wind the engine up pretty good at highway speeds and if your vehicle is really old you usually end up cruising in the slow lane. If I'm cruising around town I don't mind cruising and going slow but if I'm on the freeway usually I got a destination I want to get to, it's pretty nice having that overdrive transmission to get those RPMs down, get your fuel mileage up a little and quiet down some of the road noise. This is where a 700R4 or a 200 r4 or a 4L60E or a 4L80E really comes in handy. That being said they are not as robust as a turbo 350 but if this car isn't going to be your daily driver you got a question yourself is fuel mileage or durability a concern? And when I mentioned durability it's not like they're unreliable it's just they're not as reliable, turbo 350s you will routinely see go two or 300,000 miles 700R4's 120,000 seems to be pretty normal under normal wear and tear not being driven like a teenager owns the car.
Well, that's one of the best ways to stir up a can of worms around this forum. This calculator lets you put in speed, tire diameter, rear gear ratio and final trans ratio and get the rpm. Both the 200R4 and 700R4 have a .69 rato = rounded to 30% overdrive. https://purperformance.com/p-29669-rpm-calculator.html That said, now what do you want the car to do? Lower rear gears for more poke though the gears with the OD to cruise at a decent rpm? 3.7 or 3.5 gears for good poke and a real comfy 80 mph cruising speed for hours on end on the long roads? If you work it right you come up with a rig that lives pretty well in both worlds, It has some poke and acceleration and it cruises at highway speed without having to stop at every gas station. All the cool guys have them so I wanna get rid of my tubo 3fiddy and run and overdrive so I can be a cool guy with bragging rights at cars and coffee. "The cool guys have them and I wanna be a cool guy too" is the lamest reason to put anything on your ride.
This forum is supposed to emulate the hot rodders up to the mid 60's . No self respecting hotrodder of that time period would be caught in public with a automatic transmission , let alone an automatic overdrive . We're all just a bit phony . Simply a statement , take it for what it's worth .
For heavy cars and pickups 700 R4. For lighter cars and mini trucks 200 4R. The 700 replaced the T400. The 200 replaced the T350.
At the same time, they used what was easily available for good prices. What was cheap and plentiful 60 years ago is often rare and very expensive today, so one could focus more on working with what's available as in the 60s than working with what actually was available in the 60s.
well...not quite. The 700R4 replaced the 350, the 200-4R replaced the 180. The 4L80E replaced the 400
Tell that to the guys who raced with B&M hydros back in the day. Right now my 77 year old left knee hurts to beat hell from pushing the clutch in the Ford pickup I have been driving while my daily is down. Making me ponder the wisdom of running a stick in my 48 again.
I mean.....I have a hot rod magazine from the fifties that had had a banner of something like "shifterless roadster" or something. Was an automatic that used a choke style cable hidden above the column that worked as a shifter
It all depends on what your rearend gears are and if you intend to change them or not. Id say an overdrive automatic is not really efficient combo on a carbureted engine unless you have rearend gears 3.55 or deeper. A friend of mine had an OT El Camino with a healthy small block and 700r trans and 2.73 rearend gears. He loves it but wonders why his car gets poor mileage when his engine is turning super low rpms to move the car at 70 or 80 mph. He simply isn't running at cruise speed in the sweet spot of the engines efficiency. All of the above is moot if you are running fuel injection. They can lug an engine at lower rpms than carbs.
Maybe because the 327 is 60 years old and it's often cheaper and quicker to run a crate than to deal with a machine shop with less warranty and hoping your 60 year old parts are usable?
Thousands of sticks on the street & strip vs a few hundred confined to the strip ,does not compute ...
Naw a hot rod engine warranty=a rod that actually gets used. Not just a short jaunt to the local sonic once a weekend.
Dunno about others , mine has 55K miles on it , BTW , you can blow em up in "short (1/4 mile) jaunts".
Not really. GM B, C, D & G body cars used the Th200-4R. Vehicles weighed 3500-5K+lbs. 700 equipped F/Y body, S/T & C/K trucks of that era weighed 2600-4000lbs. TH180<3L30<4L30 had a production run from the late 60's to the early '00s and was used behind 4 bangers and small I6 engines in light duty capacity, from Opel to BMW TH200<TH200C<TH2004R paralleled 180 from '75-'90 being used mostly in midsize and fullsize RWD vehicles with large V6s and 5.0L and smaller V8s. Initially used as a lightweight replacement of the TH350, and its light duty variant TH250, it became a staple of mid/full size rwd GM applications. 180 and 200 did not share model lines.
55k in how many years? For one my 57 283 had wear ridges at 45k from 1957 to 2018 when it was pulled out for an engine we both can agree doesn't belong in a vintage car. And I often put 50k on a vehicle in under a year.....in fact one planned trip for my 54 will be 3400 miles..... pulling a trailer
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