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Does anyone know if the GMC engines(228,302) uses the same flywheel as the 261 Chevy? If not, is there any other flywheel that may fit behind it?
And what about bellhousing, do they both use the same?

The chevy engines use 6 flywheel bolts and 3 locator pins. Looking at my old manuals, some of the GMC engines may only have 4 flywheel bolts. The 235/261 engines may share the same flywheel, but I'm not sure. 6 volt and 12 volt 235/261s used different ring gears. 6V models had 139 tooth gears, and 12 models had 168 tooth gears. The starter & starter pinions are also different, to mesh up with the different ring gears.

Good luck
chip

Thanks, Chiphead. We had the 261 here, the ring gear is the same as the V8 and 250, 168 tooth, but the bolt pattern of the crank bolts is different. So no way to use one in the other. But I got no info in GMC. If some are 4 bolts, them the GMCs are different from both the 261 and the 250. As for the 235 and the 261, I've already changed one for the other, no problem. Only diferrence is in the clutch and starter ring, they both have the same bolt pattern in the crank.

As far as I know the GMC flywheel has a six bolt pattern. Also the 302 and the 270 used different flywheels

Alexandre: Bellhousing on all Chevy six 216, 235, and 261 is same bolt pattern from 37 thru 63. The flywheel and crankshaft bolt pattern is the same from 41 thru 63.

All 41 thru 54 flywheels use the wide 139 tooth ring gear and six volt starter.

All 55 thru 63 flywheels use the narrow 162 tooth ring gear and twelve volt starter.

Can't help you with GMC info, don't know! Maybe Jolly knows or can answer your questions. Jolly is the BB resident GMC man.
What do you say Jolly?

Think Chevy! :confused:

J.Keith, does the 270 or the 302 accepts a V8 flywheel?
Chevyman, thanks . I've worked on a 51 Fleetline of a friend for sometime, changes the 235 for a 261, made some changes to the car, and learned the hard way all those little differences in the starter/flywheel area. The car was swapped to a 12V sistem, so everything changed.
I'm asking because I've discovered here that the Stovebolt from chevy is not the same as the GMC.
GMC are pretty rare here,(and the 261 has been around for more than 30 years) and one time or another I do find one lost here. And it's nice to know beforehand what we are dealing with. This guy with the fleetline, he also has some ideas of dropping a bigger GMC in the car or building another 51/52 car with a GMC mill. So, I'm doing my homework before it arrives.

GMC's definetely use a four bolt flywheel. I have two 228's and fried has a 302, they all use four bolt flywheels.

All the 302s that I have use 6 flywheel bolts.
jason