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| | | Forums66 Topics128,096 Posts1,056,477 Members48,444 | | Most Online14,466 Apr 26th, 2026 | | AD Chevy Trucks Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
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on the Internet for over 30 years! and not clogged down with Ads! Again, thanks! | | | | Joined: Feb 2004 Posts: 3 Junior Member | | Junior Member Joined: Feb 2004 Posts: 3 | Hi, was just curious if any one has done a trans swap with a modern day 2004r, 700r4 etc. i have everything figured out and my concern is: will there be any clearance probs on the cab where the firewall might have to be trimmed ? i know on a smallblock swap there is. thanks....also any ideas on mounting a modern day power steering pump to the 235 other than altering 250 brackets...... | | | | | Joined: Jan 2001 Posts: 613 Member | | Member Joined: Jan 2001 Posts: 613 | i don't believe a gm automatic will bolt to a 235. | | | | | Joined: Feb 2003 Posts: 452 Shop Shark | | Shop Shark Joined: Feb 2003 Posts: 452 | Check the Langdon's link. They have adapter plates for the stovebolt. I'm not sure which trannies work. From what I've read, the OD trans have a throttle valve cable that can be finicky.
Current fleet (subject to change w/o notice) \'49 GMC 3/4-Ton , 60 Austin Healey Frog-eye Sprite (some assembly required), 2011 Dodge Avenger, 2015 Jeep Cherokee. No, they don't all run. My other ride is a (B737)no, (B767)no, A320.... Update... was Embraer E190, now Boeing B787. Knowledge is a wonderful thing, but ignorance means you don't know you can't do something.
| | | | | Joined: May 2001 Posts: 7,438 Extreme Gabster | | Extreme Gabster Joined: May 2001 Posts: 7,438 | Yes there is an adapter for such. I've mounted one behind my 248 on my '54 GMC. I haven't put the cab back on yet so I don't know about clearance problems. I haven't worked out the details of the throttle valve cable yet either but there is lots of info on the web. tvmadeez Can't help you about the ps pump. | | | | | Joined: Feb 2002 Posts: 12,029 Cruising in the Passing Lane | | Cruising in the Passing Lane Joined: Feb 2002 Posts: 12,029 | there isn't a clearance problem w/ a small block in the 55-59 trucks - they had'em originally [small blocks that is, and auto trans too]
Bill | | | | | Joined: Nov 2000 Posts: 119 Member | | Member Joined: Nov 2000 Posts: 119 | I've never done this, but I would be concerned about the engine and transmission mounting system.
When you take a long inline engine, normally supported at the front and the bellhousing, and then take away the bellhousing support and move it to the rear of the transmission, it has to put a lot of bending stress on the bellhousing area. I don't know if that is a practical or theoretical problem.
I've also heard that flexplates have to be redrilled to match the stovebolt crank, and they are prone to cracking.
The cracking could also be a problem from improper centering of the adaptor system, which can be overcome with careful measurement for concentricity with the crank.
Finally, others have claimed that modern automatics don't shift at the proper rpm points to match well with the old sixes.
Again, I've not done any of this myself, so take it for whatever you feel it is worth. Not trying to discourage anyone... just a caution before you spend your money. | | | | | Joined: May 2001 Posts: 7,438 Extreme Gabster | | Extreme Gabster Joined: May 2001 Posts: 7,438 | Locobreath, you are right about the mounts. I built solid side mounts for mine in addition to the front and rear mounts. I'm wondering how much vibration will be transfered to the drivers seat by the solid mounts.
My flexplate was custom built by Buffalo Enterprises. I don't know if Langdon re-drills them from some other application or not. There has been a lot of controversy about these kits. The only person I have actually corresponded with who has used them has a hot rod business and he strongly reccommended I not use one. Since I don't intend to hot rod I decided to give it a try. Only time will tell if I rue the decision. | | | | | Joined: Feb 2004 Posts: 3 Junior Member | | Junior Member Joined: Feb 2004 Posts: 3 | thank you very much to all who have responded. i know the small block worked back than as i have a have an original hyromatic here and it is of a different configuration, tom langdon sold me the adaptor 2 years ago and it is a real nice piece if you follow directions in installing, i did have to have the crankshaft cleaned up slightly to accept the torque converter properly. as far as the flywheel it is a redrilled nova 6 cylinder. the motor mounts (to prevent rocking motion and ripping the rear trans support mnt.) will be fabricated once i get the engine leveled and in place. i guess i will just have to wait and see what happens. my motor is at the shop and i need to spay cab asap and would have rather not do any welding and fab stuff after the spraying and have to do touch up but my boss wants it out of the shop. thank you again to all who responded to this post!!!! Respectfully, apachemark........ | | | | | Joined: Nov 2000 Posts: 119 Member | | Member Joined: Nov 2000 Posts: 119 | Having said all of that, if it was supported properly and correctly mated to the engine, the transmission isn't going to care if it is hooked to a 235 or a 250 (within reasonable power limits).
I'm really interested to see how some of these units turn out.
Another thought... there is a company that makes adaptors to put auto transmissions behind other makes of engines. They fabricate a new bellhousing and saw off the old transmission casting bellhousing, and bolt to the front of the transmission pump. Maybe someone could work up something like this to provide side mounts and proper hookup to the stovebolt.
Cletis, I'm wondering how did you provide the side mounts? Sounds like you gave things a considerable amount of thought. | | | | | Joined: May 2001 Posts: 7,438 Extreme Gabster | | Extreme Gabster Joined: May 2001 Posts: 7,438 | Here is a picture of the mount when I was building it. It is 1/4" plate with 2X2X1/4 angle iron at the frame. I used 2 bolts on each side of the angle. Of course there's another on the other side. | | |
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