1964 C30 Towing Capacity

[Chuck73080]

Originally Posted by LenDill

I have a 1964 C30 Dually completing a full restoration, replacing the 230 - I6 and 7200 lb rear H072 axle 5.14 gears, with a remanufactured 350 cid with Max Flow EFI-500 fuel injection, remanufactured 1980 14 bolt 8000lb rear dually axle with 3.73 gears, added double reservoir power brakes. All drum brake hardware rebuilt or replaced with new. New remanufactured SM420 with Novak front seal upgrade and added synchronizer between 1st and 2nd gear, final gear ratio 1.0. I am looking to tow a 5th wheel in the 5000-8000 max range. I won't be towing often, a couple of times a year between Virginia to Tennessee. GVWR on the truck plate is 10k. The trailer will have brakes. I won't be adding disc brakes, and surely looking way ahead with the setup while towing.

Let me know your thoughts on if this is doable with enough margin for a 5000-8000 fifth wheel RV.
Thanks

Would you mind sharing your source for the 14 bolt?

I'm going to swap my rear also, although I want a 3.56 (my tires are 225X75R16, 29.3" Dia.} for 2388 RPM@75 MPH with Gear Vender OD, 3062 RPM without. My 396" SBC crate engine dynos at 460 ft lbs @2400.

Here's a link to a Spicer RPM calculator.

https://spicerparts.com/calculators/...rpm-calculator

The first gear syncronizer in the SM420 sounds good, mine only has 62,000 miles but it'll be out anyway so it may be worth an exam, and synchronizer addition.

Please let us know if you have pictures posted of your truck because I would love to see it.

Chuck73080