The Stovebolt Site Forums The Shop Area Engine Shop opinion question

I have a 52 3600 which is original. I want to be able to pull my 1947 Spartan travel trailer behind it. the trailer weighs about 4500 fully loaded. recommendations to be able to pull at 60? i6 or v8? 5 speed? 3.73 or 4.11? ideas would be appreciated.

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Assuming that your brakes and suspension are OK, a 3.73 rear end and a standard 4-speed transmission (SM420) would allow you to bring it up to speed from 1st and cruise at 60 mph with a late 235 (1956-63) or 261 engine.

My opinion is based on being easily able to cruise at 60 mph with my 3.90 transmission (and a 1:1 in high gear transmission) and a 235/261 engine. I suggest the 4-speed because it might help get the fully loaded truck/trailer rolling from stop.

The 56-63 235 had more horsepower due to a higher compression head. The 261's higher lift cam in the 235 gives more horsepower and the 56-63 235's head on a 261 would give more horsepower.

What 3.73 rear end would you use?

I know nothing about which V-8 to use, and why?

the rear end is undecided right now, I did find a set of 4.56's for mine right now but I would like a little higher ratio. right now I pull it with a 3.0 liter diesel but I would rather use the old truck instead.

I'd recommend a 292 engine and a NV 3500 5 speed overdrive transmission, coupled up to a Dana Type 60 3.73 or 4.11 rear axle. You'd still have the inline 6 engine, but with enough torque to handle the towing chores nicely and an overdrive gear for good highway cruise speed. If you're considering V8 power, it seems you're not a purist for a period-correct running gear. The 292 was designed for load-pulling and/or trailer towing, and it will cruise well when paired up with the right geartrain.
Jerry

I am new to the stovebolt family. I am not familiar with the abilities of the i6. I would prefer to keep the truck the way it is . thanks for the advice.

Any particular years that would make my life easier on the install?

Are you looking for a higher ratio than 4.56? That would be a 5. 'something'. If you had inquired about a higher 'gear' I would have assumed that you were looking for something like a 3.73. If the latter is the case then you really wanted to look for a lower ratio. An example of where the confusion can come from is two-speed axles. It has 'high gear' and 'low gear', but the 'high gear' actually has a lower mathematical ratio than the 'low gear'. Clear as mud. Please don't hate me, but feel free to engage me in friendly discussion.

Jeff3600, I have a 1954 3600 currently down to the frame. I plan to use it to tow a car trailer. I am using a 1954 261 with a the higher compression 235 head (848). Transmission is a NP 540 5 speed (from a 1958 2 ton)this should solve the problem the sm420 has with the wide ratio range between 3rd to 4th which will make towing in the hills more difficult. Currently in the process of installing a Dana 60 with 3.73 gears setting pinion angle, drive shaft length and perch mounts. The Dana is from 72 Ford F250 and 3/4" wider than the stock 1954 rear axle. Measured from wheel mounting surface WHS. Except for the shock and perch mounts it is an easy swap. The rest of the truck will be original and unless you have a trained eye the engine and trans will look original also.

Due to the fact you're towing, something bigger than the 235 would be ideal. A 261 would probably be the easiest install. The 292 would require engine mounts and some fabrication. As far as transmissions, go sticking with the SM 420 should be fine. You could probably get away with a 3.42 or 3.55 rearend with the 4 speed also. The NV4500 from a newer truck would be a good upgrade, giving you overdrive.

As far a rearends go, The Dana 60 is a good option. There's plenty of them out there, and dozens of gear ratios.



I have a Full Float 14 bolt for my 3600 truck. They come in a couple different widths, the 67 and 63" versions. They had huge brake drums and shoes. If you can't find a 63 you can use your hubs (with corrected bearings) from the 3600 truck and adapt some brakes for use. GM had them in a number of gear ratios, 4.11 being the most common in the older trucks. 3.73 and 3.42 is a little more common in the newer trucks.

Another thing to consider is updating your brakes. There's a few guys out there that have successfully did their own disc brake conversions. You could use drum brakes from a 1 ton as an upgrade also.