Tom,
A couple of things. Spoa gives you 6" lift. You have to understand that this is a big lift for any truck. It will be made worse for you because you have a 410. The 410 axles are much narrower and make the car even more unstable. There are lots of hidden details with Spoa. Its not just a case of weld the perches and jobs done.
You have to think about:
Brake lines
Prop spacers
Uj angles
Shocks
Bump stops
Bam bar for rear
Steering (merc high steer is the best Z bars or any other crud is pretty much lethal)
As a rule of thumb for any inch up you want to try and get a inch extra on the wheel base.
Im not a fan of Spoa, i dont like the set up, but others do. Why do you think you need SPOA? You axles will still be just a low on the floor, and raising it that high will give a high COG and will be more likely to roll over.
If you want to fit big tires i would have a good look at Scotts build. However thats a lost of work and welding to get what he has now.
There are spring lifts on the market that are good but they do some at a cost. I run a 4-5" lift and can get my 31" rubber under it no problems.
However if you are set on Spoa, i would strongly reccomend getting some sammy axles and haveing the perches welded on them. These are wider and will give you more stability. With wheel spacers, offset rims you will be far better off that standard.
Hope this has pointed out some points to you?
Henry
