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I purchased a 1949 (1950) Chevy 3600 truck that appears to be in original configuration with an in-line 6-cylinder engine and 4 speed floor shift transmission. The title says it is a 1949 but the serial number decoding indicates it is actually a 1950. The shock configuration (tubular type) appears to confirm the 1950 rather than 1949 vintage (see photos attached). The overall thought is to have a great looking functional truck that I could drive and take to car shows.

I am in process of disassembly to identify what needs work (primarily body rust repair in the typical locations) and developing my project plans. The original concept was to convert the drivetrain to utilize a SBC 383, coupled to a NV3500 transmission, with a revised ratio (4.11) in the original rear axle, update the brakes to disk front and rear, but retain the original suspension and axle mounting/springs with the wheels and tires updated to more recent technology. An alternative concept is to retain the original 6-cylinder engine and transmission and basically restore more or less to original. I would probably still upgrade the front, and possibly rear brakes to disk as well as update the wheels and tires to more recent technology.

I suspect that there a number of opinions regarding the two concept paths and would appreciate input before I decide which path to take.

Plan for bed sides: determine location of existing box side angle strips, remove original strips, repair box sides as needed, purchase and install new box side angle strips.

Plan for cab: establish correct cab to frame spacing with front and rear cab mounting points secured, remove rusted floor sections and replace with patch panels (one area at a time), then remove cab from frame to remove rusted cab corners and replace with patch panels. More information in Sheet Metal Shop area.

Engine ID reported to be a 235 made between 1957 and 1962 for the passenger cars with 3-speed transmissions. T = Tonawanda Engine Plant; 8 = Month (August); 06 = Day; A = Regular 235 for passenger cars with 3-speed transmission. Subsequent engine block (3737004) casting and cylinder head (3866848) cast numbers determined. Also located tag that indicates it is bored 0.060 oversize, have 0.010 undersize rod journals, and I believe 0.010 undersize crank journals. Sounds like it is not worth keeping but may be able to sell all or parts. More information in Engine Shop Area.

Conflicted regarding powertrain direction.

I have a NV3500 from a 1995 GMC Sierra 4WD (with the transfer case) but adaption to 2WD is a challenge. Considering using the NV3500 with an adapter to the original mid-drive shaft (torque tube) but requires parts and machining to end up with a two-piece drive shaft that may not be ideal. Locating a manual transmission with OD for a 2WD truck application appears to be challenging and possibly expensive. Clutch actuation from the pedal to the throw out bearing will also be challenging.

Automatic transmissions seem to be readily available but newer versions are electronic which raises the question of doing a complete LS engine and transmission installation rather than using the 1991 350/383 engine option. If I go the LS route, I could purchase either an engine/transmission combination with the wiring and ECUs but programing the ECUs for the existing rear axle ratio etc. would require something I don’t know how to do. I could also consider purchasing a wrecked truck to obtain the required LS engine/transmission parts and possibly some additional items such as rear axle, seats, steering column, etc.

Anyone out there that has done an LS swap with electronic automatic transmission that could provide insight regarding fit issues and ECU programming issues would be appreciated.

PM BarnFind49

Located an NV3500 2wd transmission and plan to purchase/pick up 1/23/2022.

The engine machine shop has confirmed that my 350 block is okay, next step is to determine what block machining is required.

After decisions are made about the bore size need to work on ordering engine parts (including decision regarding 350 or 383 displacement). First blush is to go with the 383 but depending on heads and cam the increased compression ratio could be a concern (would like to retain regular gas).

Appears my driveline direction is taking shape with the 350/383 SBC engine, NV3500 manual transmission, etc. The existing (original) rear axle ratio will result in higher engine rpm at 60 mph cruise than optimum but with taller tires should be acceptable.

It has been cold here in WI so I have generally been limited to working on fenders, etc. that I can easily carry from the back shed where the truck is located to a heated garage. Primarily working on rust repair and banging out some of the larger dents. Overall the fenders are in good shape but that doesn't mean that there aren't rust issues to be resolved, primarily at the bottom edges, and some cracks.

When the weather has allowed I have started working on bracing my door openings prior to removal/replacement of floor sections and cowl panels. I have ordered and received patch panels for the floor, inner and outer cowl, fuel filler opening, and rear cab corners. My plan remains to do as much of the floor and cowl repair as possible with the cab mounted to the frame, then remove the cab to complete the cab work and also work on the frame. The frame appears to be in good condition but with all the grease and grim accumulated over the years I will not really know until I can get it cleaned up. I did find the driver's side rear running board bracket is broken below the top mounting rivets so I need to decide if I am going to repair it in place or remove it for repair.

I picked up a set of seats from a 1999 Chevy truck that include the integrated seat belts. The front and two sides of the original seat riser were previously removed. Setting the seats in roughly their intended position I think I want to raise the seats roughly 1 1/2 inches above the existing cab floor with their seat tracks against the remaining original rear seat riser. with approximately 6" between the seats. I am developing a plan for a combination seat riser/floor reinforcement structure but continuing to work through the details to ensure both structure and safety.

We have not had the best luck with the NV 3500 (or T5) trans in anything with a lot of torque and/or big rubber. Fine for cruising or showing but iffy if hammered. As far as clutch actuation is concerned the factory set up from the 60-62 Chevy pickup hydraulic system can be used or from early 90's Chevy pickups that came with the NV 3500. We used the McCloed after market hydraulic TO bearing and plumbed it in. Concerning overdrive transmissions one can still pickup the old BW 3sp OD unit at swap meets for $250-$500 and it is as strong as the T5 or 3500 and gives a final gear of 3.05 with a 4.56 or 2.88 with the 4.11. Just make sure the solenoid is good before purchase. I came to Texas 60 years ago from Minnesota and can relate to wintertime difficulties in working on old rides. First winter in Texas found out it's WAY easier to shovel sunshine.

Coilover, thanks for your input regarding the transmission. I realize that the NV3500 is somewhat limited regarding torque capacity but I have had some experience with it behind a SBC in another project and I think it should be okay for my plans for the truck. I will look for the early 90's factory clutch setup that you mentioned.

Continuing to work on patching minor rust, crack issues on sheet metal parts that I can move into my heated shop area. Considering the truck looked pretty solid as I dig into it every part seems to have some rust or crack that needs to be repaired. At least I can continue to work on the project a few hours each day and feel like it's not just waiting for warmer weather.

I ordered the rotating assembly parts required to build a 383 SBC and the machine shop is machining the block as required to clear the rods. I order dished pistons to keep the compression ratio in the 9:1 range so that I have a chance to run regular fuel rather than premium but still have not decided on cylinder heads or cam for the engine build. Unfortunately the parts I ordered are not expected to be available until May so the engine build will probably be conflicting with the cab, frame, etc. work I need to due during the warmer months.

I am working on the cab when the weather cooperates (not often) but have braced the door openings and made some preliminary plans regarding how much of the floor, firewall, inner and outer cowl panels, etc. to cut out.

Unfortunately the project is at a stage where I have a thousand ideas of things I need to consider and no ability to actually move forward on them because they are dependent on getting the cab work done enough to remove the cab from the frame, getting the frame cleaned and painted, etc. I probably need to create a detailed action plan to lay out the sequence of things that need to be done so that I don't loose track of things given the large number of sub-project activities that interact.

Started the cab patch panel work today by cutting out the floor, firewall, inner, and outer cowl panels on the passenger side. More details in the body and paint section.

I picked up the cylinder block from the machine shop and dropped off the original cylinder heads for cleaning, valve job, etc. Looking at options regarding accessory mounting (see Hi-Pro section) so that when I get the parts to start engine assembly I know what water pump rotation and length to buy.

Still plugging along on the cab repair and appear to have decided on a path forward for the passenger side. Still a fair amount of work to be done but progress is being made.

I picked up the cylinder heads from the machine shop and am now waiting for the rotating assembly parts (expected in early May) to move forward with the engine build.