1964 C30 HO72 Axle Swap to 14 Bolt
 

Hi,

Background: I am working on a 1964 C30 complete restoration and want to swap out the HO72 5.13 133 inch wheelbase DRW axle assembly to a 14 bolt DRW. I have an upgraded custom-built SM420 which addressed the front leaky seal problem and added Syncro for 1st to 2nd gear. Replacing the 230 I6 and old SM420(Original Mileage 65K) with a custom-built Gen 1 SBC. I want the option of doing light to medium towing in the 5-8k lb range with good highway speed. Online speed calculator with 3.73 gears results at 2500 rpm, 30.5 in tires and 1:0 final gear ratio on the SM420 looks reasonable for highway cruising/towing.

Question: What year and options should I look for in a 14 bolt chevy w/10.5" ring gear? Also, I am adding power brakes and discs upfront but keeping the rear on drums. I'm ok with a junkyard find, but will still have it cleaned and gone through (rebuilt), or buy a remanufactured complete assembly. In addition to that, what's your thoughts on optionally moving to 3.55 or 3.4X since I've upgraded the powerplant. Any details and advice on this conversion would be much appreciated. Thanks

Re: 1964 C30 HO72 Axle Swap to 14 Bolt
 

Welcome!

That rpm range will probably be good for that sbc. On the rear axle, I think the squarebody axles (73-87 (but also to 91 for the bigger trucks)) are almost a bolt in deal.

I'm sure someone that's actually done the swap will chime in soon.

Post up a pic of your truck!

Re: 1964 C30 HO72 Axle Swap to 14 Bolt
 

I would not go any higher than 3.73 gears in a 1 ton. Personally I would go with 4.10's in a 1 ton. The 10.5" 14 bolt was introduced in 1973 and used well into the 2000's. There are at least 3 different widths. There is the C/K 20/30 single wheel, the C/K 30 dually and the C/K 30 cab and chassis with duals. The Dana 70 is also an option that was used under GM 1 ton's.

Re: 1964 C30 HO72 Axle Swap to 14 Bolt
 

I have a 62 c30 that I swapped in a 1981 c30 14 bolt. It literally bolted in place. I replaced my u bolts but other than that I was driving the truck in a few hours.

Re: 1964 C30 HO72 Axle Swap to 14 Bolt
 

Will do. Thanks