I've wheeled a '90 K5 since the late-90's and have gone through several iterations. I bought the rig in '94 with 49k on the clock and it was all stock except for 32" mud tires and never used for anything but snowy roads. Stock Gov-lock in the rear 10-bolt grenaded pretty early in life but only after it was stolen and wheeled hard before being stripped. It was covered in mud with a big dent in the front bumper when the police found it sitting on blocks. When they pulled the rear diff cover it had a lot of water and mud in it. By the time I went on my first real trailride (as opposed to playing around in a little mud) it had the following:
Rear - Detroit Trutrac, 4.10 gears, fairly fresh rebuild, and the factory 30-spline shafts (pre-'88 or '89 had 28 spline shafts)
Front - Eaton Posi, 4.10 gears, fairly fresh rebuild, factory shafts, Warn locking hubs.
Low powered automatic and was running 33" mud radials. Didn't run it real hard but did run difficult trails and regularly feathered the brakes when applying the gas to get the limited slips to lock up. Then stepped up to 35" radial muds and slightly harder trails. I broke two front axle u-joints during this time but it was always at the tire that was down in a rut and with the wheels turned and dragging the brake. After learning to avoid that situation I ran for years on progressively harder trails with no issues.
Later swapped in a 14FF rear with welded diff and converted the front to 8-lug. Ran several more years with no issues. While I had never broke the rear 10-bolt going to the 14FF gave me more confidence. If you break the front axle at least most of the times you can still drive out of the trail in 2wd. If you break a rear axle, especially a semi-float 10 bolt, you can be really screwed.
Last iteration was going to a D60 front. Bought a complete running, but very rusty, '78 K30 SRW for $750. Pulled the D60 out and sold the 350 engine, SM465, and rear axle to recoup most of my cost. Put new bearings in the D60, rebuilt the king pins (just bushings), slapped a Lock-Right and new Spicer joints. With skinny 38" TSLs I did break one of the original and old necked down inner shafts and replaced those with Spicer non-necked down shafts. Then broke a couple 30-spline stubs so replaced those with Yukon 35 spline stubs and flanges. After those mods I've had zero issues with the D60 even after going to 39.5x15.5 TSL's.
I have a hard time recommending spending a ton of money on a 10-bolt, but that is also based on what myself and several friends have spent on 1-ton axles. I have maybe $400-$500 in a rear 14FF that includes all new bearings and seals, disk brakes, and welded diff. For the front D60 I probably have around $2,500 in it including new bearings and seals, Lock-right, 35-spline stubs and flanges, new inners and joints, etc... When it comes to rear axles I don't think there is anyway you can compare a 10-bolt to a 14FF especially considering how cheap a 14FF is. You will never make a rear 10-bolt as strong as a stock 14FF regardless of how much money you throw at it. A little different story on a front 10-bolt vs. D60 in regards to price mainly because of how much a D60 can go for. However I still question the wisdom of throwing thousands of $$ at a front 10-bolt for D44. So maybe you can make it as strong as a stock D60, but where do you go to from that point?
For the comment about the HP (high pinion) axles, generally a high pinion D44 or D60 has a stronger ring and pinion when used in a front axle application. The normal low pinion setup is designed for a rear axle and thus only one gearset. When you use the same center section in the front axle application you are now running on the coast side of the ring and pinion when driving forward, and obviously the gears were not optimized to be the strongest in this setup. The high pinion setup has the gears running on the drive, or stronger, side of the gears and thus are stronger in a front axle application. However using a HP D44 or D60 in the rear agains put you running on the coast side of the gears when driving forward.