The Stovebolt Site Forums The Shop Area Engine Shop 1950 261 to 68+ 250 swap??

have an old Babbetted bearing 261 w/automatic. found a 68+ 250. wanting to do a swap. will it work? any hidden surprises besides motor mounts?

Welcome

May have ur engine nos transposed there--216s were babbit engines--261's were full pressure larger truck engines with insert bearings. The 250 engine has different mounting points than the earlier 216/235/261 engines and will require different motor mounts. Welcome to the board.

ok, but i read somewhere that the 216s didn't come with a factory automatic tranny mated to them and this one did. hmmmm, maybe it's a 235? i know the earlier models mounted up front with a plate behind the timing cover and late models were side mounted. will the front mounting plate bolt to the later model engines? will the tranny bolt right up?

I assume this is a '50 3100. If that is correct, I don't think it was available stock with an automatic.

The early 50's cars with automatics had a full pressure motor.

What automatic transmission do you have?

ok, this is a 1950 Styleline car. it has a babetted-bearing engine and powerglide automatic transmission. this i know without a doubt....i took it out myself. nothing looked modified to make me believe that any other kind of tranny has ever been in there. the engine's connecting rods do not have insert-style rod bearings. they are soldered/tinned in and one went bad.

OK, now you're making more sense. This is mainly a truck forum, so we're not used to dealing with car questions. The automatic you've got is a cast iron case Powerglide, which won't bolt up to the later model engine. If you want to swap to the newer engine, you'll probably need to use a Turbo 350 transmission or one of the later-style overdrive automatics like a 700R4, etc. You'll need to fabricate engine/transmission mounts, and deal with things such as the enclosed driveline, rear end, etc. You'd be better off finding an insert-bearing 235 engine and installing it with the original transmission. There would be a lot less fitting and adapting involved with that swap! A Powerglide from a 55-61 V8 engine would bolt up to the late-model 6-cylinder, but it still won't solve the driveshaft adapting probl;em. Your car has an enclosed driveline, and the mid-50's transmission is made for an open driveshaft.
Jerry

No one has stated it explicitly , so I will:
The V-8 which came out in 1955 had a different bellhousing pattern than the 6 cylinders of the day. In 1963, a new line of sixes appeared which used the V-8 pattern. So, the 216, 235 and 261 (as well as the GMC 228,248,256,270,302) shared the old pattern while the 'new' sixes (230,250,292) use the same pattern as the V-8.

I once owned a '62 Chevy that was factory with a 283 and cast iron powerglide. There was an adapter ring between the transmission and the motor, and I understood there was a different ring for the sixes.

Could it be that finding a V-8 type adapter ring from an early cast-iron powerglide would allow using a 230/250/292 with the early transmission?

I've no idea, and no intention of doing such a thing, but it might Ben's problem...

so, a 55-62 six would be the best swap then?

Yep....that would work the best. Do you still have the closed driveline rearend?

oh yeah, sure do

should i try selling the babbetted bearing engine, or would it just be a waste of my time?

Well....I'm a saver...I don't throw anything away....someone might want or need it.

Offer it up for sale or free on the swap meet or E-bay....someone will take it off your hands.

Put it on Ebay in "as is" condition, with an honest report on what you think is wrong with it. You might be surprised what it will bring.
Jerry

wound up getting a 235 out of a 54 truck. it's almost installed now.