Hi guys I am fitting a 700r4 in my ‘49 wagon it currently has a ‘61 235 installed and I have the Langdons’ adapter kit My reasons for this swap are current 3 speed is shot . I’m getting older and want an auto not a stick shift for ease of driving. I already have a 700r4. I want to keep the 235 6 cyl not go v8 So the 235 has front mounts and there are mounts on flywheel housing and rear of gearbox The adapter from langdons doesn’t have facility for the side mounts and I am concerned about just having a front and rear mount I have heard that there could be issues with flex plate cracking has anyone done a conversion like this and how did you resolve the mounts Any other advise would be useful thanks
Little different situation, but I have a 261 using a similar adapter to a small block steel*****tershield and made some custom side mounts that connect to the bellhousing bolts and back to the original frame mounts. The original front mount in these cars are pretty wimpy so you definitely should do something for side mounts at the bellhousing or convert to sidemounts at the engine.
I’ve had ideas about this for awhile. Never done it before though. I’m sure someone will tell you how they did it. But my idea was to use the BH and holes as a pattern. Then lay that patten on 1/4 plate. Trace it out, center punch for 3 holes on each side. Cut out the middle and what’s not needed on top and bottom of the plate. Then go engine-adapter-transmission-mount plate then bolt it in. Ie with the mont plate last so the bolts hold it, the trans and adapter in place. You’d still need to have pads welded on for isolators etc. plus that’s a lot of weight, I’d probably still run a rear mount as well. Just my thoughts, I’m sure others have overcome the same issue.
Another thought. It has been a long time since I did mine, but don't the original bellhousing mounts bolt to the front face of the bellhousing? Could you just drill and tap holes in the front face of the adapter in the same location as the holes in the bellhousing?
Since you have a block with side mount provisions, my suggestion is to grab the engine brackets from a 61 or similar. Then fab the frame attachment onto your car using the 61ish rubber parts. add a crossmember mount under the trans, That should provide a mount system equivalent to stock 61,,
It may not have side mounts, depending on what the engine came out of. ‘I have had several 235 and 261s, even some blocks of the same years are different. I have two 1954 261 blocks, both have side mounts but only on one are they drilled and tapped. ‘I have had late block of the same year one will have the mounts cast in and an other won’t.
They sell bellhousing adapter mounts for the '55-'57 Chev cars that will fit the 700R4, and likely would be easy to adapt to the bellhousing mounts on your frame. I'd go that way, or fabricate my own bellhousing adapter mounts. No way I'd try to rely on just the trans tailhousing mount for this swap. The 700R4 will really make the 235 perform well with it's 3.07 first gear, and OD for highway cruising! https://www.avsontheweb.com/turbo-mounts-for-original-bell-housing-1955-57-chevy-car/ I'd personally use all three locations to have front, bellhousing, and trans tailshaft crossmember. Having the trans hanging back there unsupported is going to result in cracked case sooner or later.
I have no additional recommendations for the mounting, but do want to stress that you pay close attention to the TV cable installation AND adjustment. Do not try to drive it without the TV cable installed, or your 700R4 will be very short lived. You may well be aware of the criticality of having the TV cable set up right, just wanted to throw this out there in case you don't.
Thanks for the useful and prompt replies guys Just checked the 235 block and it does have the threaded bosses so I think I will try and use those mount brackets they shouldn’t be too difficult to fabricate I am aware of the need to fit and adjust the TV cable correctly I will post some pics of that set up when I get there Next job is to remove the original trans cross member and either adapt it of fabricate new one to suit 700r4 but Pendine Sands Hotrod races is less than a month away so need to think about prepping the T Modified for that 1st
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