aj2003

hey guys new to the site i have a 91 rs i just finished building a 71 vette motor im dropping in tomorrow but im swapping out the 700r4 for a th350 and it doesn't look like its going to be a direct swap. the th350 looks shorter and i know i have to swap the tail shaft housing to accommodate the torque bar but it looks like its gonna be to short. any advise/help would be greatly appreciated
thanks anthony

whatever84

http://www.summitracing.com/parts/UPI-2230-B/ Just get this and a drive shaft from a 82 F body with an automatic and your set. I got the B&M 700R4 to TH350 swap bracket but I wish I would have got this. Good luck.

Mark.

nosajwols

iTrader: (1)

I am running a TH350.

What you need is the cross member, driveshaft, and torque arm from an 82 that had a BW T10 (4 speed manual). The T10 is the same length as a short tail (car version) TH350. As for the tailstock, I am running one from a Monza that had a TH350. The Monza had a torque arm and the tailstock has the torque arm mounting holes.

Of course all the above is easy for me to say because I started with an 82 that had a T10 and I did the conversion 20 years ago when there were still Monzas in the wrecking yards. It might be hard to find all the above today but it is possible to do the conversion all bolt in and looking entirely stock.

mcbchild

iTrader: (1)

I just had the trans shop take the tail off of my old 700r4 and mount it in place of the tail on the th350 using a 2 or 3 inch aluminum spacer in between to make up the difference in length between the 700r4 and the th350. No other part are needed. Uses the same crossmember, driveshaft and has the same torque arm mount location.

sofakingdom

iTrader: (1)

http://www.bulkpart.com/Merchant2/me...350-350Cswitch

NaMaro

How much did that cost ya? I am trying a th 350 swap as well....I just don't have the original 700r4 to compare and/or interchange. Any thoughts?

Randy82WS7

a 9" tail th350 from a truck '73 up is what to use to keep same length as 700r4

so you dont have to find a 82 or 83 th200c driveshaft, or apparently 4 speed as well.

82 was not the only year of the short trannies. '83 was also a short tranny year


for an 84 up a truck th350 is way easier simpler i dont know why ppl just dont do it this way

can have a 9" tailshaft put into a 6" tailshaft th350 as well, but it requires tearing all the guts out of the case because the output shaft is the first to go into the case unfortunately.

when i put a 6" th350 in the 82 trans am i had it was simple no modifications since it was an 82 th200c car

but for 84-up cars a car th350 is not the way to go unless you already have an 82 83 driveshaft sitting around

also keep in mind that 82 crossmembers are unique and only fit under 82's

83 up was different bolt up to the subframes

just to add some trivial and fun to this




'73 to '86 2wd truck th350 is what you want to swap from a t5 or 700r4('84-up cars)

th350 and 700r4 tailshafts are not interchangeable

the only thing similar between these is that they are both 27 spline

mcbchild

iTrader: (1)

I traded in my 200r4 or 700r4 for the turbo 350 trans and they used the 200r4/700r4 tail off the old trans and installed it on the turbo 350 and added the spacer at the shop, all for $400. I am pretty sure they used the tail from the 200r4 as that is the trans I gave them out of my 1984 v-6 firebird. So I guess the tail shaft from a 200r4 or 700r4 would both work. You can get a used trans for the tail shaft off of a used trans at the boneyard or if you know someone that has a blown 200r4 or 700r4 from our cars just laying around and not being used could work also. Also, the crossmember from my 1984 Firebird v-6 200r4 and 1985 TA v-8 700r4 were the same crossmember if this helps at all. Also used the same driveshaft and yoke. Even used the same torque arm mount, but I did buy another bushing inside the mount and changed from the rubber mounting bushing in the torque arm mount to polyurethane. But I will warn you if you go with the crossmember reloc kit you listed, you may not be able to use a true dual exhaust system as the pipes from the long tube headers (If you did plain on long tubes) will not clear part of the crossmember kit listed on the link you provided. I can also tell you that by switching out to the turbo 350 trans, you now loose the ability to drive the car on the highway for any type of long distance if you run any gear above 3:42 or 3:45 because these trans have no over drive and your engine will be winding pretty high with any higher numerical gears. I am really thinking about swapping my 9 bolt rear 4:10 to a 3:45 9 bolt rear end and just keeping the 4:10 9 bolt rear end for racing as they are pretty simple to swap out.

Hope all this info I provided helps you decide the direction you want to take.

NaMaro

Wow, thanks man. You saved me a bit there! The TH350 I have located and plan on picking up this weekend is out of a '78 half ton. It does have the 9in tail. However, I have an 85 Z28. So does that make a differance in the drive shaft still? And where would I get a different crossmember for it? Also, is there anything else that I will need to do/get for the swap? All info is greatly appreciated!

Mangup

Swapped a TH350 into my '92 RS - Very simple. Keep your stock driveshaft & crossmember from the 700R4. Buy a longtail TH350 and the B&M conversion kit - Simple as that. The conversion bracket bolts in behind the TH350 case and tailshaft housing. You might also want to consider polyurethane tranny mount and torque arm bushing if you've upgraded to aftermarket torque arm. I've been using this for racing with no problems since 2003 (6.90 1/8th mile) with some additional minor rear suspension upgrades.

NaMaro

Nice. Thats what I plan on using mine for as well. Street/Strip car. By long tail, do you mean the 9 or the 12? Also, where can I find the conversion kit. And the polyurethane mount, torque arm bushing, and the aftermarket torque arm....where would I go about finding those? Do you have a shift kit or any other mods done to your trans?

whatever84

9 inch tail housing is what you will need, I used Summit racing and Jegs for everything else.

Mark.

Mangup

th350 with 9.25 inch tailshaft housing is 1/8 inch shorter than 700r4 and both are usually 27 spline, so you can reuse the 700r4 yoke & driveshaft. After hundreds of launches i haven't had any problems with the stock yoke/driveshaft (knock on wood!). Polyurethane tranny mount is made by a few different companies including Energy Suspension. The adjustable BMR tubular torque arm I have came with a polyurethane bushing included. The th350 has been modified for racing, manual valve body with B&M Console Megashifter, hardened spragg, machined with extra clutches, Kevlar band, etc. Any decent shop that does racing transmissions will know what needs to be done. The cheapest way to do the tranny is probably to buy one the right length that needs to be rebuilt and have it done yourself to specification at a good shop.

bluegrassz

iTrader: (3)

Save yourself some headaches and buy a flexable trans dipstick/tube. Stay away from the cheap chrome units.

I used the Hurst kit for the torque arm mount. Some say it works better than the B&M kit.

NaMaro

The one i'm picking up Monday has the 9 in tail. I have a crossmember from the 700r4 already. As well as a stock drive shaft. I will have to shop around to find some good deals on everything else. Anyone have a kit they don't use anymore just layin around?

bluegrassz

iTrader: (3)

If you are going to rebuild the trans, check out Dana at Probuilt Automatiics. He is a member on the board and set me up with a rebuild / transgo shift kit . I installed it my mysellf.

https://www.700r4l60e.com/store/home.php?cat=21

acline

I have an 86 TA with a 355 in it right now, i picked up a built th350 couple weeks ago i want to get everything together for when i install it, the th350 is the 9in version. So what length shifter cable do I need? and will i need any of the other mounts or parts?

JediKnight69

I realize this thread is a few years old buy I would like to say thank you to all who posted all the details. I am in the midst of rebuilding my 82 Z and want to go the th350 route.

Can anyone provide any updated information that would be useful for this conversion?

Night rider327

iTrader: (13)

I didn't read the whole thread, but here's some of my thoughts.

Yours being an '82 start with a th-350 short shaft trans..

For 84 up use a th-350 long shaft so stock 700r4/T5 driveshaft will fit.

The old B&M and hurst swap kits works great but very outdated now. Might run you a tad more but getting a crossmember and torque arm package now that takes TQ arm off the trans tail will help you sooo much later on. Just easier to deal with, easier to swap trans, easier to find correct TQ arm bracket, plus helps traction, etc.

Use a poly trans mount. I use ES poly on mine.

Use a TransGo reprogramming shift kit, not the cheapo litte B&M ones.

Don't cheap out with the torque converter, look into a custom built 9.5" or 10" converter from a place like PTC in AL. Might run you $100-200 more than a off the shelf B&M or TCI but will be well worth it.

Install a SFI cert flex plate. It's worth the $50 extra.

The B&M governor recal kit is great for truly setting your auto shift points. It's trail and error work with the weights but you will love the WOT 1-2, 2-3, and 3-2 shifts. In my th-400 using that cal kit I have my auto shifting WOT shifts set at 6400 rpm.. It still shifts early at low/part throttle but at WOT it holds to my set 6400 rpm.

Add a stacked plate style trans cooler like the B&M super cooler to yours.

dustind

Hey so i bought a 1984 camaro sport coupe with a 305 carb and A/T 700r4 transmission. i put a 289 hot cam, 200cc heads, lifters, rockes, ect pylled the stock carb and distributor out put a 600cfm edelbrock and dropped in a hei distributor. i did everything but the crank and did it all with the engine in the car. Transmission worked fine before all this work. But now my transmission will only shift to P,R,N,OD,1 BUT when its in overdrive it wont shift out of first gear. If i try to manually shift it to L1,L2,D well L2 and D do not work and sometimes feels like it pops out of first. And speedometor is not working. I just put a new filter and fluid in the transmission lastnight thinking it may help.

stealtht/a

iTrader: (1)

Really should start a new thread, no ones going to see this tacked on to a five year old zombie thread

redneckjoe

yup.

camaross396z

The most annoying part of the swap will be shortening the driveshaft. The TH350 is shorter, so in most cases you'll need to go ahead and get a new driveshaft.

project89

iTrader: (1)

9 inch tailshaft th350 will drop in place of the t5/700r4 and reuse the stock driveshaft


other then a drag race application i dont know why anyone would want to swap the 700 for a th350 , i did the swap in my car and even with low rear end gears its not all that fun driving down the highway

but my car also isnt built to go down the higway for long periods of time so it doesnt matter