I don't see a problem running both spacers for a few reasons.
1) the inner spacer has nothing to do with it, all it does is alow the use of ifs hubs on the solid axle, the spacing is for the brake rotor
So the inner spacer is irrelivant
It is relevent because you are gonna bend your knuckles and axle with that much tire spaced that far out. It may not be an issue with small tires or stock tires but when you move the wheels out that much it is increasing the leverage on the axle and with those huge tires you are gonna have problems.
3) everyone here say's the 30 spline longfield axles are the s--t
I also have the chromo hub gears
4) As for power and gearing I don't think that will be a problem for tha small block ford or the nv4500 W/ dual yota cases,
Thats why I went with the 4:88's
7) two words LIFETIME WARRANTY
Longfields are the best, but Bobby will tell you flat out you need fullsize axles. I wouldn't be surprised if he doesn't warranty your broken parts if he finds out what you are running. With a small block Ford you will have just enough power to spin the tires and completely destroy your entire drivetrain. There is no hope of your front axle surviving 4 cylinder power, let alone V-8 power. Even if your axle shafts survive, you are gonna break ring gears. Lifetime warranty isn't gonna help you when you are broke down and blocking the trail, making the hundred people trapped behind you homicidal. Toyotas work good when they are all, or mostly Toyota. The more Toyota you remove from your truck, the worse it is gonna work. All those parts frequently break with 22r motors, good luck with 4 more cylinders
![My Two Cents :twocents:](https://board.marlincrawler.com/Smileys/marlin/twocents.gif)