VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 31 block into 29 truck

Hi all, I'm putting a 31 block into my 29 1 1/2 ton truck with 4 speed transmission. Since my 29 transmission support will not mate up to the 31 what will I need between my 4 speed and this 31 block? Did 31 move to a one piece bell housing and will it just bolt in? or?? Thanks very much. I'm new to the forum. Greg

Not the question you asked but one other area to check is the size of the pilot bearing/bushing and output shaft if you are using the 31 crank. There is a difference between 31 and the earlier 3 speeds. Maybe not on the 4 speeds.

Dave

I sent you a PM with info a possible parts truck.

Cheers, Dean

I tried to do this same thing in reverse of putting a 1930 engine in a 1931. The 30 had a two piece bell housing with cast iron part that bolted to the engine and then the steel part of the bell housing bolted to the transmission. If I remember correctly the bolt pattern on the 1930 block had 4 bolts in the bell housing and the 31 had the same along with two on the top. The pilot bushing is different size and 1931 used a bearing and not a bushing. The parts book shows the same number for three and four speed bell housings on 29and 30's. I used a 30 crankshaft in my 31 and had to make a bushing to fit the crank to the 31 transmission. It can be done but takes some time to get everything correct. Good Luck, Chuick

Thanks Chuick for this helpful information. I believe that the 29 and 30 have the same setup utilizing the cast iron transmission mount and the steel bell housing to mate to the transmission. Do you know what original 31 setup was like? Did it utilize a different bell housing that bolted directly to the rear of the engine or still utilize a cast transmission mount between the engine and the steel bell housing?
Thanks Greg

Thanks for thinking of this Dave, I'll double check.
Greg

Yes.

The '31 and up used a cast iron clutch (bellhousing) housing that bolted directly to the block. That eliminated the cast part and stamped steel clutch housing. Pedal shaft was bolted to the housing instead of riveted on.

Thanks to you all for the helpful information on this. Do you know if my existing 1929 4 speed truck transmission will bolt up to a 31 bell housing as is or if Chevy made some modification there as well? I expect that it should be the same but then...

I went the other way around and put the truck engine in my 29 it fit.
Al

Thanks AL, sorry to be dense but you're confirming that my 1929 4 speed truck transmission should bolt directly to the 31 bell housing? I've got a stock 1929 1 1/2 ton truck that i'm putting the 31 block into. I'm hoping that i will only need to find a 1931 truck bell housing to make everything fit up nicely.