The Stovebolt Site Forums The Shop Area Driveline Where to start transmission swap

I've been considering storing my inline 270 and dropping in a 350 with 700-r4 transmission to my 55.1 jimmy. But there is just something so sexy about a finely rebuilt and tuned inliner.

I'd like to keep my inline after i rebuild it but im tired of it's lack of power and acceleration on the highway and the clunky 4sp tranny.

I'd like to put in an automatic 200-r4 or 700-r4. What parts and what steps do i need to take to get this accomplished. From what i've researched i need the following

Adapter plate (from Buffalo Adapters- not sure of pricing)
Different Fly Wheel
Different Starter (why cant i keep the original?)
Need a closed drive line
Different gears in the rear end
Transmission Corssmember

is it necessary to cut the floor with any of these transmissions?

I want to keep the stock shifter but use it as the auto-shifter. (i think lokar has something for this)

Also, i'd like to use the clutch pedal as the overdrive so as to keep the truck stock appearance.

Finally, i want to find a 4barrel carburetor intake for the 270, does that even exist? i have the setup (uninstalled) for a 2 zenith intake.

thanks, looking forward to this project.

Buffalo makes you a flex plate with the adapter. You need a '75 or so starter to bolt to the adapter. A '55.1 should already have an enclosed driveline with 3.90 gears. That will be adequate. A universal crossmember will work. You will have some cutting to do on the floor. If you can find a floor pan from a Hydra-Matic truck, cut the floor to fit it. You won't be able to use an SM420 shifter on an automatic but there are aftermarket floor shifters. Keeping the clutch pedal in place sounds pretty goofy to me. Yes there is a 4 bbl intake made but I'd go with 2 Zeniths.

Check out my tranny swap.

Thanks for the info. I called Buffalo and am waiting to hear back. I'm keeping the clutch pedal just to keep the car looking stock.

what is the main difference between using a TH200-4R vs a 700-4r? is there improved gas mileage?

Yea the 2 Zeniths would look pretty bad [censored].

Just got off of the [hone with Buffalo. Looks like im going with either a 200 or 700 since the gear ratio will work and the drive line is ready (just needs to be shortened)

He was mentioning that i need to identify the crank shaft in order for him to send me the correct flex plate. How do i determine which crankshaft to use?

Another note, if i do not hook up the overdrive cable to my setup, what consequences will i suffer to the car / engine other than high rpms? I know i should run the overdrive in all cases, just afraid how im going to hook it up to my throttle linkage on the double zenith setup.

thanks

Your crank shaft will have either 4 bolts or 6. What year is your 270?

From what i was told (by my grandfather, it was his) Is that it's original 1955.1 with a 270 head. However, he could be mistaken. I guess i'd have to get the casting numbers to verify the block and head.

If it is the original engine it is a 248 with a 6 bolt crank.

any indications if it really is a 240 or 270?

I'm not sure you fully understand how the overdrive works in a 700R4. The cable and the adjustment is critical on these transmissions. It controls the shift points not only the overdrive engagement. If the cable is not adjusted correctly you could damage the transmission in a very short time.
The 2004R trans was basically used in smaller engine applications, V-6's and small V-8's. It is about 4" shorter than a 700R4. It can be built to accomodate more torque. The 700R4 was used in trucks and larger cars. The electronic version is a 4L60E which came out in about 93.
Fred

Presumably, your asking about the engine being a 248 or a 270?

Post the code you find pressed into the ledge in the block that is just to the rear of where the distributor goes into the block. The engine size should be at or near the front of his code.

I do understand that the TV cable is what controls the shifting and that it is crucial to the performance. Buffalo Enterprises explained that it is difficult to get it just right on a single barrel carb. Although it can be done.

After the install, i may just take it to a reliable mechanic to get the cable hooked up properly.

So are you suggesting that a 22-r4 is a better choice for the engine? I researched that the 700 has better highway performance. Not looking for the tuck to be super torqey nor am i racing it. Just a cruiser with decent mileage and highway performance.

Thank for the tip, i'll take a look today during my lunch.

Does the head / valves have a stamp with a similar size indication?

In my experience both the 2004R and the 700R-4 perform well as conversions. It's all a mater of availability, cost, and mods needed to make them work.
You have to make a lot of modifications for either of them.
Fred

What conversion did you do? And what mods other then floor cutting and drive shaft did you have to do?

Does the truck cabin need to channeled or just the toe board opened up a bit?

Any one have info for donor cars with 700r4s, mechanical speedometer output, non-electronic shifting?

transmissionadapters.com has the complete kit to convert your inline to automatic

I'm curious as to how you intend to match the torque-tube to a non-standard transmission? As you know, the TT bolts to a receiver of sorts on the rear of the original 3 or 4sp transmission. When you go to an automatic you lose the receiver.

How do they mate up?

If it is a 55.1, it would have originally had an open drive shaft.

Lucky devil ;-)