does anyone have a 700r4 chevy trans bolted up to a Pontiacx block using an adapter?
 

Just wondering? Was it a big deal doing it? Speedway sells the adapter plate and I suppose there re others.

I came back make that pontiac, not pontiacx

Pretty common. Anyone that runs an overdrive transmission is using a Chevy to BOP adapter. The lone exception of course would be if you're running an aftermarket bellhousing on something like a 4l60e, or you have a 200r4 which has the BOP bolt pattern naturally on it's bell housing.

I run a simple Jegs adapter plate on my engine for the 4l80e. It's easy to install and works as intended.

Most adapter plates will come with spacers to add between your torque converter and possibly the pilot. If you're having a torque converter built, you can also have them add the necessary pads directly to the torque converter as well as adding to the pilot depth where necessary. If the adapter you buy does not come with a pilot extension, they can be purchased independently.

It's also important to note that the adapter reduces the number of bolts physically holding the transmission to the engine and uses some blind holes that mount the adapter to the transmission, but are not connected to the engine in any way. As a result, you have less sheer strength holding the transmission to the engine. This is typically not an issue until you start getting into a good bit of HP and you may be racing the car with very good traction. If you get to that point, a mid-plate is the better option.

Thanks that's just what I needed to know.

Or run a 4l80e with a bellhousing adapter

First one I used was back in 2000 to put a 700r4 in my '69 Firebird 400, and I now have one on my OHC L6 connecting up a 4L60e. They work fine. Bonus if you put longer alignment dowels, but typically work decently with standard ones.

I've had a 700R4 bolted to my 455 for many years now. It was very easy. I use the bowtie overdrives TV cable setup. Had to get a custom length driveshaft. I love the 700R4. My car is a street cruiser that gets highway use too. I've got a Chevy 12 bolt rear end too with 3.73 gears.

I like that you mentioned the torque converter side of things too — a lot of people overlook proper spacing and pilot engagement, and that’s where issues like vibration or premature wear can come from. Getting the converter built to spec from the start is always the cleaner approach.

My personal preference would be the 200R4...better gear ratio from 1st to 2nd.

IA2 blocks have the chevy & BOP bolt patterns, not sure about MR blocks.

Nothing wrong with using an adapter.

If you swap the bell on a trans, it's not cheap, and you are married to the case. If you ever have to swap the case, you basically have to star over.

To make a 700, 200, or even a 60e to handle decent torque, you have to spend more than using a 4L80/85e. Even if you take the controller into account.

Would you chose a TH350 over a TH400? There may be reasons in doing so, but the TH400 will almost always outlast a TH350.

Let the flaming begin. But you know it's true...


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Yes, MR blocks are dual bolt pattern..


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My TA has been in the 10s with a TH350 but almost every trans guy tells me he can build a stronger TH400 cheaper than he can a TH350. Mine was a hand me down form a Buick buddy that got it for his GS form Phoenix Transmissions.