how strong is my 70 dana 20 transfer?

[ryanNC]

I just finished my 475 hp 406 sm. and already spit the spider gears through my inspection cover on my 12 bolt. I fixed that with a Lock-Right. I now my SM465 will hold up.
I'm just wondering if I need to np205 swap now?

 

[fr8train]

I would in err. in favor of hind sight and go with the NP 205 setup. I wouldnt put it past a built mill to chew up anything. Its just the duration of replacing stuff can get real old real quick , not to mention expensive.

"Lord have mercy on my next thirty years"

 

[SilverJim]

I just finished putting an NP205 behind my SM465, but the weird thing was that when I went to put the body back on , the transfer case was too high...the body rested on the t-case! So I got a 3" body lift and all was well. This problem could have been solved by lowering the t-case i suppose, but my oil pan on my big block is already too close to the front x-member for comfort. Just thought I would throw in my limited experience with that...curious though...does anyone know if the x-members for trucks with an NP205 are different than the ones with Dana 20s?

1970 GMC Jimmy 502HO/SM465/NP205 doesn't run just yet!

 

[HarryH3]

I'm not sure what kind of abuse a Dana 20 can take, but installing the Lock-Right in the 12-bolt only fixed the current problem.

I hate to rain on your parade, but if you pound the truck with that engine and a manual tranny, next thing to happen will be bits of ring gear popping out through the inspection cover.

After blasting through 3 12-bolts in 3 years in a previous K5, I decided to figure out how to install a 14-bolt FF under my current one! I haven't managed to bust teeth off of that 10.5 inch ring gear yet.

<font color=black>HarryH3 - '75 K5</font color=black>
http://ThunderTruck.ColoradoK5.com

 

[Blazer1970]

SilverJim, having swapped from a 3 speed Saginaw/Dana 20 in my '70 Blazer to an SM465/NP205, I can tell you that the cross member for the NP205 has about an inch more drop in it to clear the 205. I started putting mine back together with the old cross member, and had the same problem you did. Fortunately I had a complete parts truck with the correct cross member. To the original question, I think the Dana 20 is pretty stout, as someone else said, the 12 bolt is probably still the weak point.

Tim

70 Blazer CST 4X4 350 SM465 NP205
87 Burb 4X4 350
01 GMC 2500HD 4X4 Duramax/Allison