The Stovebolt Site Forums The Parking Lot Big Bolts 1970 c50 bell housing

Have been reading for years but new guy. So if this should be posted somewhere else pleas move it.
So I have a 1970 C50 grain truck that blew its 350 engine. I have a 1978 454 big block I would like to put into this truck. I have removed the 350 and it had a bell housing that is stamped 3847709. It does not match my 454 engine. Does anyone know what bell housing I need to make this re-power happen? The 454 has fewer bolt holes and the pins are larger and in the block, instead of the bell housing.

Ok. So I am half an idiot. Looking at the 350 block this morning I see that the bell housing is not attached to the block. There is an adapter in front of the flywheel. So at this point it looks like I can swap in the 454.

Those gadgets are handy.

Ed

Your adapter plate from the 350 will bolt to the 454 and will bolt to the bellhousing. Your front engine mount will require modification as the bolt holes in the 350 block are in different locations that those on the 454.
I did this same swap years ago.

Thank you for the info on the front engine mount. I have not progressed to that yet. It turns out I am in need of a large 454 Flywheel. The 454 engine had a flex plate. Since the 454 flywheel is weighted I cannot use the 350 flywheel. Had a guy that said he had one, but it turned out to be for a 427, so not weighted. Have one more place to check today. He was “looking” for it yesterday. Any other tips on the swap? I am hoping it pulls a load of grain noticeably better than the 350.

I'm glad you figured it out cuz I was worried that my brain would explode, to my knowledge all of the Chevy V8's have the same bolt pattern, I've swapped big block to small block, old 6.2 diesel to newer 6.5 all with the same bolt pattern.

I believe the purpose of that adapter is twofold- - -it converts the Chevy bellhousing bolt pattern to the SAE pattern for medium and heavy duty transmissions, and also allows the use of a larger diameter flywheel and clutch assembly. If you're doing real truck stuff it's definitely an improvement.
Jerry

Farms, I ran into the same issue on mine several years ago. What I did was used my old flywheel from the 350 on the 454 - I ordered a counter balance plate.
I have used these many times in the past and never had any issues.
If you are not familiar with these, you can find them at many different aftermarket parts warehouses.
They run $20 - $40, depending on the one you need. Usually much more economic than purchasing a flywheel.
An example of one is here at summit https://www.summitracing.com/parts/ses-3-60-11-026?rrec=true (I am thinking this is the correct plate for your application).
Call them and tell them that you need one to use your 350 flywheel/flexplate on your 454 and they will give you the correct part number.

Lexadmn, thank you. That looks like what I will have to do. The 454 196 tooth flywheel is looking more like the Loch Ness. People say they have seen it, but cannot find it.

LexAdmn Perfect explanation on 454 Have seen all that long ago,kinda forgot,need the room for a real clutch. farms you might watch out if you do anything with that 350 it may have tremendous end play in the crankshaft from that tough clutch. The nodular iron cranks would wear some times so much that counterweights would bump on the main webbing. Not so much on forged steel shaft.

farms Better check end play on your 454,I never really thought about it but do you hold your clutch down when starting ?? A truck puller I know always starts his racer in neu. clutch out because of double disc race clutch. Oil has drained off of the thrust so my .02 cents worth !

If there's a salvage yard in your area that deals in big trucks, it's possible they would have the flywheel you need. or know where to source one. The larger diameter flywheel also allows a heavier duty clutch to be used, one that won't fit inside the standard size bell housing.
Jerry

Thanks everyone. I have checked all the salvage yards within 200 miles and just come up with a 427 flywheel. After checking compression on the 454 I am rebuilding it prior to installing. It goes to the machine shop next week. So for an extra $1000 or so I can make it a 496. Not sure I need that. Will have to decide soon though.