Technical Will a 700r4 bolt up to a 348?

I gots to know.

 

Chevy isn’t like Ford. Ok I’ll be fair, Chevy isn’t like BOP and C as well.

 

Yes

 

I'm not familiar with the dimension from the crankshaft to what would be the bellhousing face on a 348 with manual transmission. I ***ume its the same since you can interchange the same manual transmissions between smallblock Chevys and 348s. So the automatic transmission should bolt in place as well since a manual bellhousing is interchangable.
The thing I would want to check is if the "flexplate" for the 348 will accept the torque converter for the 700R4. The bolt pattern could be redrilled if needed, but I'm wondering about the correct spacing or depth of the torque converter into the transmission. I'm not saying it not right, just saying that I would at least check to see that all is well in that area as well as simply bolting to the engine.

 

Friend of mine has one behind his
Neutral balance 168 tooth flywheel and modified the trans crossmember.
Added the correct kick down stuff to the carb

 

Of course, why wouldn't it?

(ok, if you get a 700 from a 4 or 60 degree V6, it wont bolt up)

 

Sounds like others have actually done this conversion and it worked fine for them, so probably not an issue. I was just concerned about the differences in flexplate designs on different Chevy engines thru the years and getting the torque converter into the trans to the right depth.

 

With Chevy V8s its harder to find a bellhousing that wont work, lol. Small block, Big Block, and W motors are pretty much all interchangeable at the back of the block. The bolt pattern never really changed. Just have to then get the correct flex plate/flywheel and starter that matches the bellhousing.

 

That is a concern on the later engines such as the LS stuff, and the electronic controlled transmissions. But back in the old days (1955-mid90s) they were all the same.

 

Isn't Chevrolet just a wonderful thing squirrel

 

Only compared to Ford, Dodge, etc.

 

And if you find one of those, I need it for a customer's project.

 

The 409 in my coupe has a B&M 700r4 bolted to it. no issues at all, bolts right up. Didn't have to use a single shim on the starter either.

 

Actually, that was in the back of my mind when I mentioned there might be a difference with the 348. I actually had to deal with that issue in my sons 56 Chevy pickup. The 348/409 being kind of an oddball/niche engine, I wondered if everything was identical. Good Info.........

 

The trans bolting to the engine is fine. The flexplate bolt pattern for a 700R4 is different, so usually need to elongate the holes to make them oval shaped to be able to bolt to the original flexplate. Doubt depth will be an issue, but if it is there's enough slip in the converters to allow spacer bushings of 1/4"-3/8" easily if needed.
I elongated the holes in the flexplate on my 350 Chev in my '39 Chev maybe 3/16" out wider to make it work. Just a die grinder and a burr worked for it.

 

or get the flexplate for a 350....they generally have both sets of bolt holes for smaller and larger converters

 

I'm putting together a 348/350 combo. I'm about to go to a couple of swap meets. How can i identify a 350 flex plate? is there a part number or some stamping that would help me? Look for the two sets of bolt holes enough?

 

Question do 348s have the bolt holes for a block starter?

 

The 348 was introduced after the Turboglide, so they had starter bolt holes....

 

Great information, there is a 348 for sale on kijji that’s our Craig’s list. The idea is planted,thanks everyone.

 

I'm not sure the 700R4 converters fit either set of holes on the TH350 flex plates with dual patterns?
But there are flexplates for sale through numerous suppliers that state they fit almost any Chevy automatic converter, and they're mostly under $100.

Here's a great resource for flexplate info at Speedway's site:
https://www.speedwaymotors.com/the-...-big-block-chevy-engine-flexplate-guide/28655

 

700 and 350 converter bolt pattern is the same. The early Powerglide and TH400 are larger.

 

If they're the same then I have no idea why the brand new flexplate for my 350 Chev with one piece rear main seal didn't match up to the 700R4 converter I have? I would have expected there would only be one flexplate for this era SBC.

 

you tried both sets of holes? Strange...

 

Mine didn't have two sets of holes. Since it's specific for a SBC with 1 piece rear main seal they don't come with two sets of holes. These are externally balanced since the one piece main seal engines use an externally balanced flywheel.
I thought there would only be one flywheel pattern, since there was only one automatic trans during those years of the SBC. But it the bolt pattern was too small, and had to be elongated to allow my 700R4 converter to bolt up.

 

Nope. There were both 153, and 168-tooth flywheels in that era, and more than one size of torque converter (car/truck, etc.)

 

Added fun...some of the trucks with the TH400 used a 6 bolt converter, which will not fit the TH350 or 700R4 converter bolt pattern.

Without seeing exactly what you had, it's kind of hard to guess what went wrong.

 

Yes, I actually meant one bolt pattern for the 168 tooth. I realize there was a 153 tooth for some smaller engines.