As part of the "winter upgrades" to my '54 Chevy truck, I'd like to replace the TH350 that's in there with an automatic overdrive... namely a 700R4 or a 200R4. Currently the truck is turning almost 4000 RPM's on the highway, so something's gotta give! A local HAMBer has generously stepped up and offered me a 700R4 from an '86 Monte Carlo. It comes complete with the stock converter. This brings up a series of questions: 1. What are the differences between the "early" and "late" 700R4's? I think they made the switchover in '87? Is that correct? 2. Does this ****** have a lockup converter? Everything I've read has told me that all factory 700R4's did, but I'd like to double-check. 3. I'm thinking about purchasing a TV cable kit ($110) and wiring kit ($70) from Bowtie Overdrives. Worth the money? Waste of time? Will I need anything else to hook it up? 4. Can I use the flexplate from my TH350? Thanks in advance! Ed PS- This is going behind a mild performance (325HP?) 350 SBC so I'm not really worried about strength issues.
That ****** does have a lock up converter. I do not know what the differences were, but I am running an early model in my 48 coupe and have had no problems with it. Check around on the prices of the cable and converter lock up kit. I bought mine from TCI and the pressure switch went the first year, they did make it good.
All 700's are lock-up type. Yes you must use it for transmission life. The 87 and up used the auxilary valve body and most builders will only use these. If you are using the unit you already have, you'll have to hook up the TV cable to a carb bracket, shorten your driveshaft, your flexplate will work, crossmember and transmission mount will have to be fabbed. The 700 is larger than the th350 so clearances may be an issue.
The 700 started out with a bunch of problems, which GM "upgraded" over the years. So, the newer the better. There were some major changes such as the input shaft getting bigger, an aux valve body added, etc. For a mild 350 engine as long as the trans is in good shape you'll be ok. I think the trick is to avoid the real early ones, '86 should be a safe bet, ***uming it's been rebuilt sometime in recent history. It will have a lock up. The TV cable is critical to make the trans live, so it's probably a wise expenditure to buy an engineered kit. The internal solenoid wiring is different on most of the ******s, so you need to get all the right parts on it, buying a kit is easier than having to scrounge the parts and info. It'll bolt to your 350 flexplate. You'll have to have the driveshaft shortened if you have a short tail 350. You'll have to move the trans crossmember back 2" also. The filler tube is different, you'll have to change that. Existing cooler lines should work, but you'd want to make sure the cooler is big enough and flush it and the lines out.
Thanks for the replies. I had a lengthy chat with a tech at Bowtie Overdrives on the way home from work yesterday and I think it's settled. I'm going to use the '86 trans with thier TV and wiring kits. I was a little concerned about the strength of the '86 unit, but since I learned that all the external connections are the same between all years, I figure "what the hell." Even if I blow this one up, it'll just be a matter of replacing the trans. None of the fab work would be wasted nor would any newly-purchased parts would go unused. Thanks for listening! Ed
Not to be a smart @$^ but a LOT of the 86 Monte Carlos had the 200R4....few had the 700R4...I realize we are talking about a 20 year old car and anything could be switched.....( ...are 86's almost 20 years old ..? ) .
The Jalopy Journal
