Putting car on jacks

[motco]

Yes you would need to be proficient in welding but you don't need to be a coded welder to build a set of these ramps. You have proven working examples so we'd just need to copy them
In my day job I'm an engineering surveyor specializing in lifting equipment. The weak points on your ramps isn't the quality of the welds, although it obviously comes into play in the overall summary, but I'm drawn to the amount of steel around the holes that the pivot bolts go through.

You sound like a chap who knows about stresses...

 

[Nodzed]

Do those stands get the front of the car high enough to drop the gearbox? What make are they?

my thoughts exactly Rob

 

[motco]

I would think there's ample room for a gearbox drop. I've done it on several other cars on ordinary ramps or axle stands so the amount of lift here is more than adequate.